TWI553738B - Half A manufacturing method of a conductor device, and a semiconductor device - Google Patents

Description

Semiconductor device manufacturing method and semiconductor device

The present invention relates to a method of fabricating a semiconductor device and a semiconductor device.

In the process of manufacturing a mesa type semiconductor device, a method of manufacturing a glass layer for passivation covering a pn junction exposed portion is known (for example, refer to Patent Document 1).

FIG. 12 and FIG. 13 are views for explaining a method of manufacturing these conventional semiconductor devices. 12(a) to 12(d) and Figs. 13(a) to 13(d) are diagrams of the respective steps.

As shown in FIG. 12 and FIG. 13 , the conventional semiconductor device manufacturing method includes, in order, a “semiconductor substrate forming step”, a “channel forming step”, a “glass layer forming step”, and a “photoresist formation”. Step, "Oxide film removal step", "roughened region forming step", "electrode forming step", and "semiconductor substrate cutting step". Hereinafter, a method of manufacturing a conventional semiconductor device will be described in the order of the steps.

(a) Semiconductor substrate forming process

First, a p ⁺ -type diffusion layer 912 is formed by diffusing a p-type impurity from a surface of one side of an n ^- -type semiconductor substrate (n ^- type germanium substrate) 910; and, by diffusing an n-type impurity from a surface of the other side, The n ⁺ -type diffusion layer 914 forms a semiconductor body in which a pn junction parallel to the main surface is formed. Thereafter, oxide films 916 and 918 are formed on the surfaces of the p ⁺ -type diffusion layer 912 and the n ⁺ -type diffusion layer 914 by thermal oxidation (refer to FIG. 12( a )).

(b) Channel formation process

Next, a predetermined lift portion is formed at a predetermined portion of the oxide film 916 by a photo-etching method. After the etching of the oxide film, the etching of the semiconductor body is continued, thereby forming a channel 920 having a depth exceeding the pn junction from the surface of one side of the semiconductor substrate (refer to FIG. 12(b)).

(c) Glass layer forming process

Next, on the surface of the trench 920, a layer composed of a glass composite for semiconductor bonding protection is formed on the inner surface of the trench 920 and the surface of the semiconductor substrate in the vicinity thereof by electrophoresis, and at the same time, the semiconductor bonding is performed by firing. The layer made of the glass composite for protection forms a glass layer 924 for passivation (refer to FIG. 12(c)).

(d) Photoresist formation process

Next, a photoresist 926 covering the surface of the glass layer 924 is formed (refer to FIG. 12(d)).

(e) Oxide film removal process

Next, the oxide film 916 is etched using the photoresist 926 as a mask to remove the oxide film 916 located at the portion 930 where the nickel plating electrode film is formed (refer to FIG. 13(a)).

(f) roughening area forming process

Next, the surface of the semiconductor substrate on the portion 930 where the nickel-plated electrode film is formed is roughened to form a roughened region 932 which improves the adhesion between the nickel-plated electrode and the semiconductor substrate (see FIG. 13(b)).

(g) Electrode forming process

Next, the semiconductor substrate is subjected to nickel plating, an anode electrode 934 is formed on the roughened region 932, and a cathode electrode 936 is formed on the other surface of the semiconductor substrate (refer to FIG. 13(c)). . Annealing of anode electrode 934 and cathode electrode 936 is carried out in nitrogen and at a temperature of, for example, 600 degrees.

(h) Semiconductor substrate cutting process

Then, the semiconductor substrate is cut at the central portion of the glass layer 924 by dicing or the like, and the semiconductor substrate is chip-cut to form a mesa-type semiconductor device (pn diode) (refer to FIG. 13). (d)).

As described above, the conventional semiconductor device manufacturing method includes a step of forming a channel 920 having a depth exceeding a pn junction from a surface on a side on which a semiconductor substrate of a pn junction parallel to the main surface is formed (refer to FIG. 12(a) And FIG. 12(b)); and a step of forming a passivation glass layer 924 covering the pn junction exposed portion inside the trench 920 (refer to FIG. 12(c)). Therefore, according to the conventional method for manufacturing a semiconductor device, after the glass layer 924 for passivation is formed inside the trench 920, the mesa-type semiconductor device having a high withstand voltage can be manufactured by cutting the semiconductor substrate.

However, as a glass material used for the glass layer for passivation, the following conditions must be satisfied: (a) can be fired at a suitable temperature; (b) resistant to a drug used in the process; (c) In order to prevent bending of the wafer in the process, a linear expansion coefficient having a coefficient of linear expansion close to 矽 (especially an average linear expansion coefficient at 50 ° C to 550 ° C is close to the linear expansion coefficient of 矽); and (d) Excellent insulation. Therefore, in the past, "a glass material containing lead ruthenate as a main component" has been widely used.

However, "a glass material containing lead ruthenate as a main component" contains negative environmental impact. With a large lead, it is conceivable that in the near future, "a glass material containing lead ruthenate as a main component" will be banned.

Therefore, although it is also conceivable to use a lead-free glass material to form a glass layer for passivation, it satisfies (a) can be fired at a suitable temperature; (b) is resistant to a drug used in the process; (c) a linear expansion coefficient having a linear expansion coefficient close to 矽 in order to prevent bending of the wafer in the process (particularly, an average linear expansion coefficient at 50 ° C to 550 ° C is close to a linear expansion coefficient of 矽); and (d) It is difficult to have all of these conditions such as excellent insulation, and a method of forming a glass layer for passivation using a lead-free glass material has not been applied to mass production of a semiconductor device for power. This is also true.

Moreover, it has been clarified by the inventors of the present invention that in the case of forming a glass layer for passivation using a glass material containing no lead, in the process of firing a layer composed of a glass composite to form a glass layer Depending on the composition of the glass layer and the firing conditions, there is a problem that bubbles are easily generated from the boundary surface between the semiconductor substrate and the glass layer. In order to solve such a problem, it is necessary to add a component having a defoaming action (for example, nickel oxide, zirconium oxide, or the like). However, depending on the combination of the glass components, there may be cases where it may not be added. Not applicable.

Further, it has been clarified by the inventors of the present invention that in the case where a glass layer for passivation is formed using a glass material containing no lead, the composition of the glass layer and the firing conditions are different (the composition of the glass: when When the glass is highly SiO2-containing, the firing conditions are performed in a short time, and there is a problem that the reverse leakage current increases. In other words, it has been clarified that if it is necessary to perform firing for a long period of time (for example, three hours), there is a problem that the reverse leakage current increases.

11 leading technical literature

Patent literature

Patent Document 1 Japanese Patent Laid-Open Publication No. 2004-87955

Therefore, the present invention has been made in view of the above circumstances, and an object of the invention is to provide a method for manufacturing a semiconductor device and a semiconductor device, which can be manufactured and used in the conventional "lead bismuth citrate" using a lead-free glass material. The glass material is also a high-voltage semiconductor device.

Further, an object of the present invention is to provide a method of manufacturing a semiconductor device and a semiconductor device, which may be generated from a boundary surface between a semiconductor substrate and a glass layer in a process of firing a layer made of a glass composite to form a glass layer. Regardless of the composition of the glass layer or the firing conditions, it is possible to suppress the component having a defoaming action such as nickel oxide without adding or adding a small amount (for example, 2.0 mol% or less).

Further, an object of the present invention is to provide a semiconductor device manufacturing method and a semiconductor device capable of producing a stable semiconductor device having a low reverse leakage current regardless of the composition of the glass layer or the firing conditions.

The present invention provides a method of manufacturing a semiconductor device, comprising: in a first step, preparing a semiconductor element having a pn junction exposed portion having a pn junction exposed; and a second step of forming a pn junction exposed portion In the third step, a layer made of a glass composite for semiconductor junction protection is formed on the insulating layer, and then a layer made of the glass composite for semiconductor junction protection is fired on the insulating layer. A glass layer is formed, wherein the glass composite for protecting a semiconductor junction is made of glass fine particles, the glass fine particles being formed from a melt obtained by melting a raw material, the raw material containing at least SiO ₂ , Al ₂ O ₃ , B ₂ O ₃ , ZnO, and an oxide containing at least two kinds of alkaline earth metals of CaO, MgO, and BaO, and substantially containing no Pb, As, Sb, Li, Na, K, and semiconductor junction protection The glass composite does not contain any one of the ingredients as a filler.

In the method for producing a semiconductor device, it is preferable that the content of SiO ₂ in the glass composite for semiconductor junction protection is in the range of 41.1 mol% to 61.1 mol%, and the content of Al ₂ O ₃ is in 7.4 mol% to 17.4. In the range of mol%, the content of B ₂ O ₃ is in the range of 5.8 mol% to 15.8 mol%, the content of ZnO is in the range of 3.0 mol% to 24.8 mol%, and the content of oxide of alkaline earth metal is 5.5 mol%. ~15.5 mol% range.

In the method for producing a semiconductor device, it is preferable that the content of SiO ₂ in the glass composite for semiconductor junction protection is in the range of 49.5 mol% to 64.3 mol%, and the content of B ₂ O ₃ is in 8.4 mol% to 17.9. In the range of mol%, the content of Al ₂ O ₃ is in the range of 3.7 mol% to 14.8 mol%, the content of ZnO is in the range of 3.9 mol% to 14.2 mol%, and the content of oxide of alkaline earth metal is 7.4 mol%. ~12.9 mol% range.

In the method of manufacturing a semiconductor device, it is preferable that the glass composite for protecting a semiconductor junction does not substantially contain a polyvalent element as a defoaming agent.

In the method of fabricating the semiconductor device, the multivalent element preferably includes V, Mn, Sn, Ce, Nb, and Ta.

In the method of fabricating the semiconductor device, the material preferably contains substantially no P.

In the method of manufacturing a semiconductor device, it is preferable that the raw material contains substantially no Bi.

In the method of fabricating the semiconductor device, the semiconductor bonding protection glass The glass composite preferably does not contain an organic binder.

In the method of manufacturing a semiconductor device, in the third step, it is preferable to fire a layer made of the glass composite for semiconductor junction protection at a temperature of 900 ° C or lower.

In the method of fabricating the semiconductor device, the insulating layer is preferably made of tantalum oxide.

In the method of manufacturing a semiconductor device, in the second step, it is preferable that the insulating layer is formed to have a thickness in a range of 5 nm to 100 nm.

In the method of manufacturing a semiconductor device, in the third step, it is preferable to form a layer composed of the glass composite by an electrophoresis method.

In the method of manufacturing a semiconductor device, in the second step, it is preferable that the insulating layer is formed to have a thickness in a range of 5 nm to 60 nm.

In the method of fabricating the semiconductor device, the first step preferably includes a step of preparing a semiconductor body having a pn junction parallel to the main surface; and forming a depth from the surface of one side of the semiconductor substrate exceeding the Preferably, the channel of the pn junction forms a step of forming the exposed portion of the pn junction on the inner surface of the trench, and the second step preferably includes forming an exposed portion of the pn junction on an inner surface of the trench In the step of the insulating layer, in the third step, it is preferable to include a step of forming the glass layer on the insulating layer.

In the method of manufacturing a semiconductor device, in the second step, the insulating layer is preferably formed by a thermal oxidation method.

In the method of manufacturing a semiconductor device, in the second step, the insulating layer is preferably formed by a deposition method.

In the method of fabricating the semiconductor device, the first step is preferably included in the semiconductor The step of forming the pn junction exposed portion on the surface of the body substrate, and the second step package preferably includes a step of forming the insulating layer covering the exposed portion of the pn junction on the surface of the semiconductor substrate, and in the third step, Preferably, the step of forming the glass layer on the insulating layer is included.

In the method of manufacturing a semiconductor device, in the second step, the insulating layer is preferably formed by a thermal oxidation method.

In the method of manufacturing a semiconductor device, in the second step, the insulating layer is preferably formed by a deposition method.

Further, the present invention also provides a semiconductor device including: a semiconductor element having a pn junction exposed portion exposed by a pn junction; an insulating layer formed to cover the exposed portion of the pn junction; and being a glass layer formed by forming a layer made of a glass composite for semiconductor bonding protection on the insulating layer, and then firing the layer made of the glass composite for semiconductor bonding protection. The glass composite for protecting a semiconductor junction is composed of glass fine particles obtained by melting a melt obtained from a raw material containing at least SiO ₂ , Al ₂ O ₃ , and B. ₂ O ₃ , ZnO, and an oxide containing at least two kinds of alkaline earth metals of CaO, MgO, and BaO, and substantially containing no Pb, As, Sb, Li, Na, and K, and the glass composite for semiconductor junction protection does not contain Any one of the raw materials is used as a filler.

According to the method for manufacturing a semiconductor device and the semiconductor device of the present invention, it can be seen from the examples described later that the use of a glass material containing no lead can be produced as high as in the case of using a conventional glass material containing lead ruthenate as a main component. A voltage-resistant semiconductor device.

That is, the method of manufacturing a semiconductor device and the semiconductor device according to the present invention, All of these conditions can be met: (a) capable of firing at a suitable temperature; (b) resistance to the drug used in the process; (c) having a line close to the enthalpy in order to prevent bending of the wafer in the process The linear expansion coefficient of the expansion coefficient (especially the average linear expansion coefficient at 50 ° C to 550 ° C is close to the linear expansion coefficient of 矽); and (d) has excellent insulation.

Further, according to the method of manufacturing a semiconductor device and the semiconductor device of the present invention, since an insulating layer having higher wettability than the semiconductor substrate exists between the semiconductor substrate and the glass layer, the layer made of the glass composite is fired. It is not easy to generate bubbles from the boundary faces of the semiconductor substrate and the glass layer in the process of forming the glass layer. Therefore, the generation of such bubbles can be suppressed without adding or adding a small amount (2.0 mol% or less) of a component having a defoaming action such as nickel oxide.

Further, according to the method for fabricating a semiconductor device and the semiconductor device of the present invention, since an insulating layer exists between the semiconductor substrate and the glass layer, the insulating property is improved, and it is also known from the examples described later that the composition of the glass layer and According to the firing conditions, it is possible to manufacture a stable semiconductor device having a low reverse leakage current. In other words, even when the content of SiO ₂ is 55 mol% or more, a stable semiconductor device having a low reverse leakage current can be manufactured even when the firing time is set to about 15 minutes.

Further, according to the method for fabricating a semiconductor device and the semiconductor device of the present invention, a glass layer is formed by firing a layer composed of a glass composite for semiconductor junction protection composed of glass fine particles, which is obtained by melting a raw material. The raw material is prepared by containing at least SiO ₂ , B ₂ O ₃ , Al ₂ O ₃ , ZnO, CaO, MgO, and an oxide containing at least two alkaline earth metals of BaO, and substantially does not contain Pb, As, Sb, Li, Na, K. Therefore, it can be seen from the examples described later that the glass layer can be fired at a relatively low temperature. Therefore, it is difficult to crystallize the glass layer during the firing of the glass layer, so that it is possible to produce a stable low reverse leakage current. Semiconductor device.

Further, according to the method for manufacturing a semiconductor device and the semiconductor device of the present invention, the glass layer is formed by firing a layer made of a glass composite for semiconductor junction protection which does not contain any one of the raw materials as a filler. Therefore, the glass layer is difficult to crystallize during the firing of the glass layer, so that a stable semiconductor device having a low reverse leakage current can be manufactured.

Further, according to the method for manufacturing a semiconductor device and the semiconductor device of the present invention, since a semiconductor device having a layer composed of lead-free glass (glass containing no Pb) having a lower electrolysis rate than lead-containing glass can be manufactured, the present invention is When a semiconductor device is molded by a resin to form a resin-packaged semiconductor device, high-density is not induced at the boundary surface between the mold resin and the glass layer and the boundary between the glass layer and the semiconductor layer during the high-temperature reverse bias test. As a result, it is possible to obtain a higher temperature than a conventional resin-molded semiconductor device in which a semiconductor device is formed by using a "glass material containing lead ruthenate as a main component" and then the semiconductor device is molded by a resin. The effect of increased reverse bias tolerance.

Further, according to the method for manufacturing a semiconductor device and the semiconductor device of the present invention, since a glass composite which does not substantially contain Li, Na, or K is used, it is known from the examples (Evaluation Project 10) described later that it is in a glass composite. Even if B (boron) is contained, for example, B (boron) does not diffuse from the glass layer into the crucible during the firing of the glass composite, so that a highly reliable semiconductor device can be manufactured.

Further, in the method of manufacturing a semiconductor device and the semiconductor device of the present invention, at least some specific components (SiO ₂ , B ₂ O ₃ , Al ₂ O _{3 ,} etc.) include not only the case where only some of the specific components are contained, but also It is included in the case where the glass composite contains not only the specific components but also the components which may be usually contained.

Further, in the method of manufacturing a semiconductor device and the semiconductor device of the present invention, substantially no specific elements (Pb, As, Sb, etc.) are included, and some specific elements are not contained as components, but the above specific conditions are not excluded. The element is mixed as an impurity into the raw material of each component constituting the glass.

Further, in the method of manufacturing a semiconductor device and the semiconductor device of the present invention, the absence of certain specific elements (Pb, As, Sb, etc.) means an oxide which does not contain the specific element, and the nitrogen of the specific element. Compound.

Further, in the method of manufacturing a semiconductor device and the semiconductor device of the present invention, the inclusion of any one of the raw materials as a filler means that, for example, when the component is SiO ₂ , the component SiO _{2 is not} used as the SiO _{2 .} It is contained in a landfill, a packing, a filler, an additive, and the like which are composed of fine particles.

100, 200, 900‧‧‧ semiconductor devices

110, 910‧‧‧n ^- type semiconductor substrate

112, 912‧‧‧p ⁺ type diffusion layer

114, 914‧‧‧n ^- type diffusion layer

116, 118, 916, 918‧‧ ‧ oxide film

120, 920‧‧‧ channel

121, 218‧‧‧ insulation

124, 220, 924‧‧ ‧ glass layer

126, 926‧‧‧Photoresist

130, 930‧‧‧The part where the nickel-plated electrode film is formed

132, 932‧‧‧ roughened areas

134, 934‧‧‧Anode electrode

136, 936‧‧‧ cathode electrode

210‧‧‧n ⁺ type semiconductor substrate

212‧‧‧n ^- type epitaxial layer

214‧‧‧p ⁺ diffusion layer

216‧‧‧n ⁺ type diffusion layer

222‧‧‧anode electrode layer

224‧‧‧Cathode electrode layer

B‧‧‧bubble

1 is a view for explaining a method of manufacturing a semiconductor device according to the first embodiment, FIG. 2 is a view for explaining a method of manufacturing the semiconductor device according to the first embodiment, and FIG. 3 is a view for explaining the manufacture of the semiconductor device of the second embodiment. FIG. 4 is a view for explaining a method of manufacturing the semiconductor device of the second embodiment; FIG. 5 is a graph showing conditions and results of the embodiment; and FIG. 6 is for explaining the inside of the glass layer 124 in the preliminary evaluation. FIG. 7 is a photograph for explaining bubble B generated inside the glass layer 124 in the formal evaluation; FIG. 8 is a cross-sectional TEM photograph of a portion including the semiconductor substrate and the glass layer; 9 is a view showing a reverse current in the embodiment; FIG. 10 is a view showing a result of a high-temperature reverse bias test; and FIG. 11 is a view showing an impurity concentration distribution in a depth direction from a surface of the crucible; A diagram for explaining a method of manufacturing a conventional semiconductor device will be described. FIG. 13 is a view for explaining a method of manufacturing a conventional semiconductor device.

Hereinafter, a method of manufacturing a semiconductor device and a semiconductor device of the present invention will be described based on embodiments shown in the drawings.

Embodiment 1

The method for manufacturing a semiconductor device according to the first embodiment includes a first step of preparing a semiconductor element having a pn junction exposed portion having a pn junction exposed, a second step of forming an insulating layer covering the pn junction exposed portion, and a third step, After forming a layer made of a glass composite for semiconductor junction protection on the insulating layer, the layer made of the glass composite for semiconductor junction protection is fired to form a glass layer on the insulating layer. In the method of manufacturing a semiconductor device according to the first embodiment, a mesa-type pn diode is manufactured as a semiconductor device.

1 and 2 are views for explaining a method of manufacturing a semiconductor device according to the first embodiment. 1(a) to 1(d) and Figs. 2(a) to 2(d) are process diagrams.

As shown in FIG. 1 and FIG. 2, the manufacturing method of the semiconductor device according to the first embodiment is sequentially performed: "semiconductor substrate preparation step", "channel formation step", "insulation layer formation step", "glass layer formation step", "Photoresist forming step", "oxide film removing step", "roughened region forming step", "electrode forming step", and "semiconductor substrate cutting step". Next, the manufacturing method of the semiconductor device according to the first embodiment will be in the order of the steps. Be explained.

(a) Semiconductor substrate preparation process

First, a p ⁺ -type diffusion layer 112 is formed by diffusing a p-type impurity from a surface of one side of an n-type semiconductor substrate (n-type germanium substrate) 110; and, by diffusing an n-type impurity from a surface of the other side, it is formed. The n ⁺ -type diffusion layer 114 prepares a semiconductor substrate in which a pn junction parallel to the main surface is formed. Thereafter, oxide films 116 and 118 are formed on the surfaces of the p ⁺ -type diffusion layer 112 and the n ⁺ -type diffusion layer 114 by thermal oxidation (refer to FIG. 1( a )).

(b) Channel formation process

Next, a predetermined opening portion is formed in a predetermined portion of the oxide film 116 by photolithography. After the oxide film is etched, the semiconductor substrate is continuously etched, and a channel 120 having a depth exceeding the pn junction is formed from the surface of one side of the semiconductor substrate (refer to FIG. 1(b)). At this time, the pn junction exposed portion A is formed on the inner surface of the channel.

(c) Insulation layer forming process

Next, an insulating layer 121 made of a tantalum oxide film is formed on the inner surface of the trench 120 by a thermal oxidation method using dry oxygen (DryO ₂ ) (refer to FIG. 1( c )). The thickness of the insulating layer 121 is set in the range of 5 nm to 60 nm (for example, 20 nm). The insulating layer 121 was formed by discharging the semiconductor substrate into a diffusion furnace, flowing oxygen gas, and treating at a temperature of 900 ° C for 10 minutes. When the thickness of the insulating layer 121 is less than 5 nm, there may be a case where the effect of reducing the reverse current is not obtained. On the other hand, when the thickness of the insulating layer 121 exceeds 60 nm, in the subsequent glass layer forming process, There is a case where a layer composed of a glass composite cannot be formed by electrophoresis.

(d) Glass layer forming process

Secondly, the semiconductor substrate on the inner surface of the channel 120 and its vicinity by electrophoresis A layer made of a glass composite for semiconductor junction protection is formed on the surface, and a layer made of the glass composite for semiconductor junction protection is fired to form a glass layer 124 for passivation (see FIG. 1(d)). The firing temperature was set to 900 °C. Further, when a layer made of a glass composite for semiconductor junction protection is formed on the inner surface of the trench 120, such a layer composed of a glass composite for semiconductor junction protection is formed: the inner surface of the trench 120 is covered by the insulating layer 121. . Therefore, the pn junction exposed portion A located inside the trench 120 is in a state of being covered by the glass layer 124 through the insulating layer 121.

As a glass composite for semiconductor junction protection, a glass composite for semiconductor junction protection comprising glass fine particles obtained by melting a raw material containing at least SiO ₂ or Al is used. ₂ O ₃ , B ₂ O ₃ , ZnO, and an oxide containing at least two alkaline earth metals of CaO, MgO and BaO, and substantially free of Pb, As, Sb, Li, Na, K, and containing no raw materials Any one of the components is used as a filler for semiconductor bonding protection glass composite.

As such a glass composite for semiconductor junction protection, it is preferable that the content of SiO ₂ is in the range of 41.1 mol% to 61.1 mol%, and the content of Al ₂ O ₃ is in the range of 7.4 mol% to 17.4 mol%, B The content of ₂ O ₃ is in the range of 5.8 mol% to 15.8 mol%, the content of ZnO is in the range of 3.0 mol% to 24.8 mol%, and the content of oxide of alkaline earth metal is in the range of 5.5 mol% to 15.5 mol%. A glass composite for semiconductor junction protection in which the content of nickel oxide is in the range of 0.01 mol% to 2.0 mol%. Further, as the oxide of the alkaline earth metal, it is preferable to use a CaO content in the range of 2.8 mol% to 7.8 mol%, a MgO content in the range of 1.1 mol% to 3.1 mol%, and a BaO content of 1.7 mol%. An oxide of an alkaline earth metal in the range of 4.7 mol%.

As a glass composite for semiconductor junction protection, a semiconductor junction which does not substantially contain a polyvalent element (for example, V, Mn, Sn, Ce, Nb, and Ta) as a foaming agent is used. Combined glass composite for protection. Further, a glass composite for semiconductor junction protection which does not contain an organic binder is used.

As a raw material of the glass composite for semiconductor junction protection, it is preferable to use a raw material which does not substantially contain P. Further, it is preferred to use a raw material that does not substantially contain Bi.

Further, in this case, the inclusion of at least some specific components (SiO ₂ , B ₂ O ₃ , A1 ₂ O _{3 ,} etc.) includes not only the case where only the specific components are contained, but also includes not only the glass composite. The particular ingredients also further contain the ingredients that may normally be present. In addition, the fact that certain specific elements (Pb, As, Sb, etc.) are not substantially contained means that the specific elements are not contained as a component, but the specific elements are not excluded from being mixed into the raw materials of the components constituting the glass. . In addition, the absence of certain specific elements (Pb, As, Sb, etc.) refers to oxides that do not contain certain specific elements, and nitrides of certain specific elements. Further, the inclusion of any one of the raw materials as a filler means that, for example, when the component is SiO ₂ , the component SiO _{2 is} not contained as a filler, a filler, a filler, or a filler composed of SiO ₂ fine particles. Materials, etc.

Here, the content of SiO ₂ is set in the range of 41.1 mol% to 61.1 mol% because when the content of SiO ₂ is less than 41.1 mol%, the chemical resistance may be lowered, the insulating property may be lowered, etc.; when SiO ₂ When the content exceeds 61.1 mol%, the firing temperature tends to increase.

In addition, the content of Al ₂ O ₃ is set in the range of 7.4 mol% to 17.4 mol% because when the content of Al ₂ O ₃ is less than 7.4 mol%, the chemical resistance may be lowered and the insulating property may be lowered. When the content of Al ₂ O ₃ exceeds 17.4 mol%, there is a tendency that the firing temperature becomes high.

Further, the content of B ₂ O ₃ is set in the range of 5.8 mol% to 15.8 mol% because when the content of B ₂ O ₃ is less than 5.8 mol%, there is a tendency that the firing temperature becomes high; when B ₂ When the content of O ₃ exceeds 15.8 mol%, boron may diffuse into the semiconductor substrate in the step of firing the glass layer, resulting in a decrease in insulation properties.

Further, the content of ZnO is set in the range of 3.0 mol% to 24.8 mol% because when the content of ZnO is less than 3.0 mol%, the tendency of the firing temperature to become high may occur; when the content of ZnO exceeds 24.8 mol% It may cause a decrease in chemical resistance, a decrease in insulation, and the like.

In addition, the content of the oxide of the alkaline earth metal is set in the range of 5.5 mol% to 15.5 mol% because when the content of the oxide of the alkaline earth metal is less than 5.5 mol%, the firing temperature may become high. When the content of the oxide of the alkaline earth metal exceeds 15.5 mol%, the chemical resistance may be lowered, the insulation property may be lowered, or the like.

Further, in the oxide of an alkaline earth metal, the content of CaO is set in the range of 2.8 mol% to 7.8 mol% because when the content of CaO is less than 2.8 mol%, the tendency of the firing temperature to become high may occur. When the content of CaO exceeds 7.8 mol%, the chemical resistance may be lowered, the insulation may be lowered, or the like.

In addition, the content of MgO is set in the range of 1.1 mol% to 3.1 mol% because when the content of MgO is less than 1.1 mol%, the chemical resistance may be lowered, the insulating property may be lowered, and the like; when the content of MgO exceeds 3.1 In the case of mol%, there is a tendency that the firing temperature becomes high.

In addition, the content of BaO is set in the range of 1.7 mol% to 4.7 mol% because when the content of BaO is less than 1.7 mol%, the firing temperature may become high; when the content of BaO exceeds 4.7 mol When it is %, it may cause a decrease in chemical resistance and a decrease in insulation properties.

In addition, the content of the nickel oxide is set in the range of 0.01 mol% to 2.0 mol% because: when the content of the nickel oxide is less than 0.01 mol%, the "battery joint protection" formed by electrophoresis in the firing is performed. In the process of using a layer composed of a glass composite, it may be difficult to suppress the occurrence of bubbles from the boundary surface with the semiconductor substrate; when the content of nickel oxide exceeds At 2.0 mol%, it may be difficult to produce a homogeneous glass.

The glass composite for semiconductor junction protection of the first embodiment can be produced as follows. That is, the raw materials (SiO ₂ , Al(OH) ₃ , H ₃ BO ₃ , ZnO, CaCO ₃ , Mg(OH) ₂ , BaO, and NiO (nickel oxide) are blended according to the above-described composition ratio (molar ratio), and After sufficiently stirring using a mixer, the mixed raw materials are placed in a platinum crucible which is raised in a furnace to a predetermined temperature (for example, 1550 ° C), and melted for a predetermined time. Thereafter, the melt is discharged from the water-cooling roll to obtain a sheet. The glass flakes are formed. Thereafter, the glass flakes are pulverized to a predetermined average particle diameter using a bowl mill or the like to obtain a powdery glass composite. Then, the obtained powdery glass composite is directly obtained. It is used as a glass composite for semiconductor junction protection.

(e) Oxide film removal process

Next, after the photoresist 126 covering the surface of the glass layer 124 is formed, the photoresist 126 is used as a mask to etch the oxide film 116, thereby placing the portion 130 where the nickel plating electrode film is formed. The oxide film 116 is removed (refer to FIG. 2(a)).

(f) roughening area forming process

Next, the surface of the semiconductor substrate located at the portion 130 where the nickel plating electrode film is formed is roughened to form a roughened region 132 for improving the adhesion between the nickel plating electrode and the semiconductor substrate (refer to FIG. 2(b) ).

(g) Electrode forming process

Next, the semiconductor substrate is subjected to nickel plating to form the anode electrode 134 on the roughened region 132, and at the same time, the cathode electrode 136 is formed on the other side surface of the semiconductor substrate (refer to Fig. 2(c)). Annealing of anode electrode 134 and cathode electrode 136 in nitrogen and at, for example, 600 degrees Perform at temperature.

(h) Semiconductor substrate cutting process

Then, the semiconductor substrate is cut at the central portion of the glass layer 124 by dicing or the like, and the semiconductor substrate is sliced to form a semiconductor device (a mesa-type pn diode) 100 (see FIG. 2(d)).

The semiconductor device 100 according to the first embodiment can be manufactured as described above.

According to the method for manufacturing a semiconductor device and the semiconductor device according to the first embodiment, it is understood from the examples described later that the use of a glass material containing no lead can produce and use a conventional "glass material containing lead ruthenate as a main component". The same high-voltage semiconductor device.

In other words, according to the method for manufacturing a semiconductor device and the semiconductor device according to the first embodiment, all of the conditions can be satisfied: (a) firing can be performed at a suitable temperature (for example, 900 ° C or lower); (b) in the process. The drug to be used is resistant; (c) a linear expansion coefficient having a coefficient of linear expansion close to 矽 in order to prevent bending of the wafer in the process (especially a line having an average linear expansion coefficient close to 矽 at 50 ° C to 550 ° C) The expansion coefficient); and (d) have excellent insulation properties. In addition, in this case, when a glass composite for semiconductor junction protection containing SiO ₂ and B ₂ O _{3 in a} total amount of 55 mol% or more is used as the glass composite for semiconductor junction protection, the chemical resistance is improved.

Further, according to the method of manufacturing a semiconductor device and the semiconductor device according to the first embodiment, since the insulating layer 121 having higher wettability than the semiconductor substrate exists between the semiconductor substrate and the glass layer 124, the glass is fired by firing. It is not easy to generate bubbles from the boundary faces of the semiconductor substrate and the glass layer 124 during the formation of the layer of the composite to form the glass layer. Therefore, it is possible to suppress without adding or adding a small amount (2.0 mol% or less) of a component having a defoaming action such as nickel oxide. The production of such bubbles.

Further, according to the method of manufacturing a semiconductor device and the semiconductor device according to the first embodiment, since the insulating layer 121 exists between the semiconductor substrate and the glass layer 124, the insulating property is improved, and it is also known from the examples described later that the glass is not used. Both the composition of the layer and the firing conditions can produce a stable semiconductor device having a low reverse leakage current. In other words, even when the content of SiO ₂ is 55 mol% or more, a stable semiconductor device having a low reverse leakage current can be manufactured even when the firing time is set to about 15 minutes.

Further, according to the method for manufacturing a semiconductor device and the semiconductor device according to the first embodiment, a glass layer is formed by firing a layer composed of a glass composite for semiconductor junction protection composed of glass fine particles, which is obtained by melting a raw material. The raw material is prepared by containing at least SiO ₂ , B ₂ O ₃ , Al ₂ O ₃ , ZnO, CaO, MgO, and an oxide containing at least two alkaline earth metals of BaO, and substantially does not contain Since Pb, As, Sb, Li, Na, and K, it can be seen from the examples described later that the glass layer can be fired at a relatively low temperature, so that the glass layer is difficult to crystallize during the firing of the glass layer. Therefore, it is possible to manufacture a stable semiconductor device having a low reverse leakage current.

Further, according to the method for manufacturing a semiconductor device and the semiconductor device according to the first embodiment, the glass layer is formed by firing a layer made of a glass composite for semiconductor junction protection which does not contain any one of the raw materials as a filler. The glass layer is difficult to crystallize during the firing of the glass layer, so that a stable semiconductor device having a low reverse leakage current can be manufactured.

Further, according to the method of manufacturing a semiconductor device and the semiconductor device according to the first embodiment, it is possible to manufacture lead-free glass having a lower electrolysis rate than lead-containing glass (excluding In the case of the semiconductor device of the first embodiment, when the semiconductor device according to the first embodiment is molded by a resin to form a resin-molded semiconductor device, the mold resin and the mold resin are subjected to a high-temperature reverse bias test. The boundary surface of the glass layer and the boundary surface between the glass layer and the semiconductor layer do not induce high-density ions, and as a result, the semiconductor device is fabricated by using a "glass material containing lead ruthenate as a main component". Compared with the conventional resin-molded semiconductor device formed by resin molding, the effect of improving the high-temperature reverse bias resistance can be obtained.

Further, according to the method for manufacturing a semiconductor device and the semiconductor device according to the first embodiment, since a glass composite that does not substantially contain Li, Na, or K is used, it is known from the later-described embodiment (evaluation project 10) that the glass composite is used. Even if B (boron) is contained, for example, B (boron) does not diffuse from the glass layer into the crucible during the firing of the glass composite, so that a highly reliable semiconductor device can be manufactured.

Embodiment 2

In the method of manufacturing a semiconductor device according to the second embodiment, in the same manner as the method of manufacturing the semiconductor device according to the first embodiment, the first step is sequentially included, and a germanium semiconductor device having a pn junction exposed portion having a pn junction exposed is prepared. Forming an insulating layer covering the exposed portion of the pn junction; and forming a layer formed of the glass composite for semiconductor junction protection on the insulating layer in the third step, and firing the layer composed of the glass composite for semiconductor junction protection A method of manufacturing a semiconductor device in which a glass layer is formed on an insulating layer. However, in the method of manufacturing a semiconductor device according to the second embodiment, unlike the method of manufacturing a semiconductor device according to the first embodiment, a planar type pn diode is manufactured as a semiconductor device.

3 and 4 are views for explaining a method of manufacturing the semiconductor device of the second embodiment. 3(a) to 3(d) and Figs. 4(a) to 4(d) are diagrams of the respective steps.

As shown in FIG. 3 and FIG. 4, the manufacturing method of the semiconductor device according to the second embodiment is sequentially performed: "semiconductor substrate preparation step", "p ⁺ type diffusion layer formation step", "n ⁺ type diffusion layer formation step", "insulation". The layer forming step, the "glass layer forming step", the "etching step", and the "electrode forming step". Next, a method of manufacturing the semiconductor device according to the second embodiment will be described in the order of steps.

(a) Semiconductor substrate preparation process

First, a semiconductor substrate in which an n ⁻ -type epitaxial layer 212 is laminated is prepared on the n ⁺ -type semiconductor substrate 210 (refer to FIG. 3( a )).

(b) p ⁺ type diffusion layer forming process

Next, after the mask M1 is formed, a p-type impurity (for example, boron ions) is introduced into the predetermined region on the surface of the n ⁻ -type epitaxial layer 212 by ion implantation through the mask M1. Thereafter, a p ⁺ -type diffusion layer 214 is formed by thermal diffusion (refer to FIG. 3(b)).

(c) n ⁺ type diffusion layer forming process

Next, after the mask M2 is formed while the mask M1 is removed, n-type impurities (for example, arsenic ions) are introduced into the predetermined region on the surface of the n ^- type epitaxial layer 212 by ion implantation through the mask M2. Thereafter, an n ⁺ -type diffusion layer 216 is formed by thermal diffusion (refer to FIG. 3(c)). At this time, the pn junction exposed portion A is formed on the surface of the semiconductor substrate.

(d) Insulation layer formation process

Next, after the mask M2 is removed, a surface of the n ⁻ -type epitaxial layer 212 (and the back surface of the n ⁺ -type germanium substrate 210) is formed by a tantalum oxide film by a thermal oxidation method using dry oxygen (DryO ₂ ). The insulating layer 218 (refer to FIG. 3(d)). The thickness of the insulating layer 218 is set in the range of 5 nm to 60 nm (for example, 20 nm). The insulating layer 218 is formed by placing the semiconductor substrate in a diffusion furnace, flowing oxygen gas, and treating at a temperature of 900 ° C for 10 minutes. When the thickness of the insulating layer 218 is less than 5 nm, there may be a case where the effect of reducing the reverse current is not obtained. On the other hand, when the thickness of the insulating layer 218 exceeds 60 nm, in the subsequent glass layer forming process, There is a case where a layer composed of a glass composite cannot be formed by electrophoresis.

(e) Glass layer forming process

Next, on the surface of the insulating layer 218, a layer composed of a glass composite for semiconductor bonding protection similar to the case of the first embodiment is formed by electrophoresis, and then a layer composed of the glass composite is fired to form passivation. A glass layer 220 is used (refer to Fig. 4(a)). The firing temperature is set to, for example, 900 °C.

(f) etching process

Next, after the mask M3 is formed on the surface of the glass layer 220, the glass layer 220 is etched (refer to FIG. 4(b)), and then the insulating layer 218 is etched (refer to FIG. 4(c)). Thus, the insulating layer 218 and the glass layer 220 are formed in a predetermined region of the surface of the n ^- -type epitaxial layer 212.

(g) Electrode forming process

Next, after the mask M3 is removed, the anode electrode 222 is formed in a region surrounded by the glass layer 220 on the surface of the semiconductor substrate (refer to FIG. 2(c)), and the cathode electrode 224 is formed on the back surface of the semiconductor substrate. Annealing of anode electrode 222 and cathode electrode 224 is carried out in nitrogen at a temperature of, for example, 600 degrees.

(h) Semiconductor substrate cutting process

Subsequently, the semiconductor substrate is cut by dicing or the like, and the semiconductor substrate is sliced to form a semiconductor device (planar pn diode) 200 (refer to FIG. 4(d)).

According to the above method, the semiconductor device 200 according to the second embodiment can be manufactured.

According to the method for manufacturing a semiconductor device and the semiconductor device according to the second embodiment, it is understood from the examples described later that the use of a glass material containing no lead can produce and use a conventional "glass material containing lead ruthenate as a main component". The same high-voltage semiconductor device.

In other words, the semiconductor device manufacturing method and the semiconductor device according to the second embodiment can satisfy all of the conditions similar to the semiconductor device manufacturing method and the semiconductor device according to the first embodiment: (a) can be fired at a suitable temperature; (b) resistance to the drug used in the process; (c) linear expansion coefficient (especially average at 50 ° C to 550 ° C) having a coefficient of linear expansion close to 矽 in order to prevent bending of the wafer in the process The coefficient of linear expansion is close to the coefficient of linear expansion of tantalum; and (d) has excellent insulation.

Further, according to the method of manufacturing a semiconductor device and the semiconductor device according to the second embodiment, since the insulating layer 218 having higher wettability than the semiconductor substrate exists between the semiconductor substrate and the glass layer 220, the first embodiment is related to the first embodiment. In the method of manufacturing a semiconductor device and the semiconductor device, in the process of firing a layer made of a glass composite to form a glass layer, it is not easy to generate bubbles from the boundary surface between the semiconductor substrate and the glass layer 220. Therefore, the generation of such bubbles can be suppressed without adding or adding a small amount (2.0 mol% or less) of a component having a defoaming action such as nickel oxide.

Further, according to the method of manufacturing a semiconductor device and the semiconductor device according to the second embodiment, since the insulating layer 218 is present between the semiconductor substrate and the glass layer 220, it is the same as the method of manufacturing the semiconductor device and the semiconductor device according to the first embodiment. The insulation property is improved, and it is also known from the examples described later that a stable semiconductor device having a low reverse leakage current can be manufactured regardless of the composition of the glass layer and the firing conditions. In other words, even when the content of SiO ₂ is 55 mol% or more, a stable semiconductor device having a low reverse leakage current can be manufactured even when the firing time is set to about 15 minutes.

Further, according to the method for manufacturing a semiconductor device and the semiconductor device according to the second embodiment, a glass layer is formed by firing a layer made of a glass composite for semiconductor junction protection composed of glass fine particles, which is obtained by melting a raw material. The raw material is prepared by containing at least SiO ₂ , B ₂ O ₃ , Al ₂ O ₃ , ZnO, CaO, MgO, and an oxide containing at least two alkaline earth metals of BaO, and substantially does not contain Pb, As, Sb, Li, Na, and K. Therefore, similarly to the method of manufacturing a semiconductor device and the semiconductor device according to the first embodiment, the glass layer can be fired at a relatively low temperature, so that the glass layer is fired. In the process, the glass layer is difficult to crystallize, and thus, it is possible to manufacture a stable semiconductor device having a low reverse leakage current.

Further, according to the method of manufacturing a semiconductor device and the semiconductor device according to the second embodiment, the glass layer 220 is formed by firing a layer made of a glass composite for semiconductor junction protection which does not contain any one of the raw materials as a filler. Therefore, similarly to the method of manufacturing a semiconductor device and the semiconductor device according to the first embodiment, it is difficult to crystallize the glass layer during the firing of the glass layer, and thus it is possible to manufacture a stable semiconductor device having a low reverse leakage current.

In the semiconductor device manufacturing method and the semiconductor device according to the second embodiment, the semiconductor device according to the second embodiment is molded by resin molding to form a resin package. In the case of a semiconductor device, high-density ions are not induced at the boundary surface between the mold resin and the glass layer and the boundary surface between the glass layer and the semiconductor layer during the high-temperature reverse bias test, and as a result, When a semiconductor material is used as a semiconductor material in which a lead bismuth citrate is a main component, the high-temperature reverse bias resistance can be improved as compared with a conventional resin-molded semiconductor device in which the semiconductor device is molded by a resin.

Further, according to the method for manufacturing a semiconductor device and the semiconductor device according to the second embodiment, since a glass composite that does not substantially contain Li, Na, or K is used, it is known from the later-described embodiment (evaluation project 10) that the glass composite is used. Even if B (boron) is contained, for example, B (boron) does not diffuse from the glass layer to the crucible during the firing of the glass composite, so that a highly reliable semiconductor device can be manufactured.

Embodiment 3

In the method of manufacturing a semiconductor device according to the third embodiment, the semiconductor device of the pn junction exposed portion having the pn junction exposed is prepared in the same manner as the method for manufacturing the semiconductor device according to the first embodiment, and the second step is performed to form a cover. In the third step, a layer made of a glass composite for semiconductor bonding protection is formed on the insulating layer, and then a layer made of the glass composite for semiconductor bonding protection is fired, and the insulating layer is formed. A method of manufacturing a semiconductor device on which a glass layer is formed. Further, as a glass composite for semiconductor junction protection, a glass composite for semiconductor junction protection comprising glass fine particles obtained by melting a raw material, the raw material containing at least SiO, is used. ₂ , B ₂ O ₃ , Al ₂ O ₃ , ZnO, CaO, MgO, and an oxide containing at least two alkaline earth metals of BaO, and substantially no Pb, As, Sb, Li, Na, K, and A glass composite for semiconductor junction protection which does not contain any one of the raw materials as a filler.

However, in the method of manufacturing a semiconductor device and the semiconductor device according to the third embodiment, the configuration of the raw material of the glass fine particles is different from the method of manufacturing the semiconductor device and the semiconductor device according to the third embodiment.

In other words, in the method of manufacturing a semiconductor device and the semiconductor device according to the third embodiment, the raw material used as a raw material of the glass fine particles is a content of SiO ₂ in a range of 49.5 mol% to 64.3 mol%, and a content of B ₂ O ₃ . In the range of 8.4 mol% to 17.9 mol%, the content of Al ₂ O ₃ is in the range of 3.7 mol% to 14.8 mol%, and the content of ZnO is in the range of 3.9 mol% to 14.2 mol%, and the oxide of alkaline earth metal The content is in the range of 7.4 mol% to 12.9 mol%.

This raw material contains all of CaO, MgO, and BaO as an oxide of an alkaline earth metal. Further, the content of CaO is in the range of 2.0 mol% to 5.3 mol%, the content of MgO is in the range of 1.0 mol% to 2.3 mol%, and the content of BaO is in the range of 2.6 mol% to 5.3 mol%. Further, the total value of the content of SiO _{2 and} the content of B ₂ O ₃ in the raw material is in the range of 65 mol% to 75 mol%. The average linear expansion coefficient in the temperature range of 50 ° C to 550 ° C of the glass composite for semiconductor bonding protection is in the range of 3.33 × 10 ^-6 to 4.08 × 10 ^-6 .

As described above, the method of manufacturing the semiconductor device according to the third embodiment and the configuration of the raw material of the glass fine particles of the semiconductor device are different from the method of manufacturing the semiconductor device according to the first embodiment, but the method of manufacturing the semiconductor device according to the first embodiment Similarly, the first step includes a first step of preparing a semiconductor element having a pn junction exposed portion having a pn junction exposed, a second step of forming an insulating layer covering the exposed portion of the pn junction, and a third step of forming a semiconductor junction protection on the insulating layer. After a layer made of a glass composite, a method of manufacturing a semiconductor device in which a layer composed of a glass composite for semiconductor bonding is fired and a glass layer is formed on the insulating layer is used. Further, the glass composite for semiconductor junction protection is a glass composite for semiconductor junction protection comprising glass fine particles obtained by melting a raw material obtained by melting a raw material containing at least SiO ₂ and B. ₂ O ₃ , Al ₂ O ₃ , ZnO, CaO, MgO, and an oxide containing at least two alkaline earth metals of BaO, and substantially containing no Pb, As, Sb, Li, Na, K, and containing no raw materials Any one of the components is used as a filler for semiconductor bonding protection glass composite. Therefore, it has the same effects as the manufacturing method of the semiconductor device and the semiconductor device according to the first embodiment.

In other words, according to the method for manufacturing a semiconductor device and the semiconductor device according to the third embodiment, it is also possible to provide a glass material containing no lead, and it is possible to manufacture and use conventional lead bismuth citrate. The glass material of the composition is also a high-voltage semiconductor device. In other words, according to the semiconductor device manufacturing method and the semiconductor device according to the third embodiment, it is possible to satisfy all of the conditions similar to the semiconductor device manufacturing method and the semiconductor device according to the first embodiment: (a) can be at a suitable temperature (for example, 900). (C) is fired; (b) is resistant to the drug used in the process; (c) has a linear expansion coefficient close to the linear expansion coefficient of the crucible (especially at 50 ° C) in order to prevent bending of the wafer in the process. The average linear expansion coefficient at ~550 ° C is close to the linear expansion coefficient of 矽; and (d) has excellent insulation.

Further, according to the semiconductor device manufacturing method and the semiconductor device according to the third embodiment, since the insulating layer having higher wettability than the semiconductor substrate exists between the semiconductor substrate and the glass layer, the semiconductor device according to the first embodiment In the same manner as in the semiconductor device, in the process of firing a layer made of a glass composite to form a glass layer, it is not easy to generate bubbles from the boundary surface between the semiconductor substrate and the glass layer. Therefore, the generation of such bubbles can be suppressed without adding or adding a small amount (2.0 mol% or less) of a component having a defoaming action such as nickel oxide.

Further, according to the method for manufacturing a semiconductor device and the semiconductor device according to the third embodiment, since the insulating layer exists between the semiconductor substrate and the glass layer, the insulating method is the same as the semiconductor device according to the first embodiment, and the insulating device is insulated. Further, it is also known from the examples described later that a stable semiconductor device having a low reverse leakage current can be manufactured regardless of the composition of the glass layer and the firing conditions. In other words, even when the content of SiO ₂ is 55 mol% or more, a stable semiconductor device having a low reverse leakage current can be manufactured even when the firing time is set to about 15 minutes.

Further, according to the method for manufacturing a semiconductor device and the semiconductor device according to the third embodiment, the glass layer is formed by firing a glass composite for semiconductor junction protection composed of glass fine particles, which is obtained by melting the raw material. The raw material is prepared by containing at least SiO ₂ , B ₂ O ₃ , Al ₂ O ₃ , ZnO, CaO, MgO, and an oxide containing at least two alkaline earth metals of BaO, and substantially does not contain Pb, In the same manner as the semiconductor device manufacturing method and the semiconductor device according to the first embodiment, the semiconductor composition for protection of the semiconductor device, which is a filler, does not contain any one of the raw materials, and the like. Since the glass layer can be fired at a relatively low temperature, it is difficult to crystallize the glass layer during the firing of the glass layer, and thus, it is possible to manufacture a stable semiconductor device having a low reverse leakage current.

Further, according to the method for manufacturing a semiconductor device and the semiconductor device according to the third embodiment, the glass layer 124 is formed by firing a layer made of a glass composite for semiconductor junction protection which does not contain any one of the raw materials as a filler. Therefore, similarly to the method of manufacturing a semiconductor device and the semiconductor device according to the first embodiment, it is difficult to crystallize the glass layer during the firing of the glass layer, and thus it is possible to manufacture a stable semiconductor device having a low reverse leakage current.

In the method of manufacturing a semiconductor device and the semiconductor device according to the third embodiment, the semiconductor device according to the third embodiment is molded by resin molding in the same manner as in the case of the semiconductor device manufacturing method and the semiconductor device according to the first embodiment. In the resin-packaged semiconductor device, high-density ions are not induced at the boundary surface between the mold resin and the glass layer and the boundary surface between the glass layer and the semiconductor layer during the high-temperature reverse bias test. In the case of using a semiconductor device using "a glass material containing lead ruthenate as a main component", it is possible to obtain a high-temperature reversal in comparison with a conventional resin-molded semiconductor device in which the semiconductor device is molded by resin molding. The effect of increased bias tolerance.

Further, according to the method for manufacturing a semiconductor device and the semiconductor device according to the third embodiment, since a glass composite that does not substantially contain Li, Na, or K is used, it is known from the later-described embodiment (evaluation project 10) that the glass composite is used. Even if B (boron) is contained, for example, B (boron) does not diffuse from the glass layer into the crucible during the firing of the glass composite, so that a highly reliable semiconductor device can be manufactured.

Example

Sample preparation

Figure 5 is a graph showing the conditions and results of the examples. The raw materials were blended according to the composition ratios shown in Examples 1 to 11 and Comparative Examples 1 to 6 (refer to Fig. 5), and then thoroughly stirred by a mixer, and then the mixed raw materials were placed in an electric furnace and raised to a predetermined temperature. Melt in a platinum crucible at a temperature of 1350 ° C to 1550 ° C for 2 hours. Thereafter, the melt was allowed to flow out from the water-cooling roll to obtain a sheet-like glass piece. Then, the glass piece was pulverized by a ball mill to a powder having an average diameter of 5 μm to obtain a powdery glass composite.

Further, the raw materials used in the examples are SiO ₂ , Al ₂ O ₃ , H ₃ BO ₃ , ZnO, CaCO ₃ , MgO, BaCO ₃ , NiO (nickel oxide), ZrO ₂ , PbO, K ₂ O, and Na ₂ O.

2. Evaluation

Each of the glass composites obtained by the above method was evaluated for the following evaluation items. Further, regarding the evaluation items 5, 6, 8, and 9 in the evaluation items 1 to 9, in the examples 1 to 11, the glass layer was formed on the insulating layer, and in the comparative examples 1 to 6, the semiconductor layer was directly formed. A glass layer is formed. The firing of the glass layer was carried out at a temperature of 800 ° C to 900 ° C, and the firing time was set to 15 minutes. Further, the glass composites of Examples 1 to 3 are glass composites contained in the glass composite used in the first embodiment, and the glass composites of Examples 4 to 11 are contained in the glass composite used in the third embodiment. Glass composite. Further, the glass composite of Comparative Example 1 is a conventional "glass composite containing lead ruthenate as a main component". Further, the glass composite of Comparative Example 2 is a conventionally known "lead-free glass composite" (zinc-based passivation glass GP014 manufactured by Nippon Electric Glass). Further, the glass composite of Comparative Example 3 was the same as the glass composite of Example 6. Further, the glass composite of Comparative Example 4 was a glass composite containing the glass composite of Example 6 and containing 3.0 mol% of NiO (nickel oxide). Further, the glass composite of Comparative Example 5 was the same as the glass composite of Example 1. Further, the glass composite of Comparative Example 6 is a glass composite (SiO ₂ -Ba ₂ O ₃ -K ₂ O-Na ₂ O-based glass composite) containing both B and an alkali metal.

(1) Evaluation project 1 (environmental load)

One of the objects of the present invention is to enable a semiconductor device having a high withstand voltage similar to that of the conventional "glass material containing lead ruthenate as a main component" by using a glass material containing no lead. Therefore, when the lead component is not contained, it is evaluated as "○" (indicating "good"), and when the lead component is contained, it is evaluated as "x" (indicating "not good").

(2) Evaluation project 2 (firing temperature)

If the firing temperature is too high, it will have a large influence on the semiconductor device during manufacturing. Therefore, when the firing temperature is below 900 ° C, it is evaluated as "○", and when the firing temperature exceeds 900 ° C, it is evaluated as "×". .

(3) Evaluation project 3 (chemical resistance)

When the glass composite shows poor solubility to both aqua regia and electroplating solution, it is evaluated as "○" is evaluated as "X" when it exhibits solubility to at least one of aqua regia and a plating solution.

(4) Evaluation item 4 (average linear expansion coefficient)

A sheet-like glass plate was produced by the melt obtained in the above section "1. Preparation of sample", and the average linear expansion coefficient of the glass composite at 50 ° C to 550 ° C was measured using the sheet-shaped glass plate. As a result, when the difference between the average linear expansion coefficient of the glass composite of 50 ° C to 550 ° C and the average linear expansion coefficient of 矽 (3.73 × 10 ^-6 ) is 0.7 × 10 ^-6 or less, it is evaluated as "○". When the difference exceeds 0.7 × 10 ^-6 , it is evaluated as "x". The measurement of the average linear expansion coefficient was carried out by using a thermomechanical analyzer TMA-60 manufactured by Shimadzu Corporation, and a single crystal of a length of 20 mm was used as a standard sample by a full expansion measurement method (temperature rising rate: 10 ° C/min).

(5) Evaluation project 5 (with or without crystallization)

In the process of fabricating a semiconductor device (pn diode) by the same method as the method of manufacturing a semiconductor device according to the first embodiment, when crystallization is not performed and vitrification is completed, "○" is evaluated, and crystallization is performed. When the vitrification is not completed, it is evaluated as "X".

(6) Evaluation project 6 (with or without bubble generation)

A semiconductor device (pn diode) was produced by the same method as the method of manufacturing a semiconductor device according to the first embodiment, and it was observed whether or not bubbles were generated inside the glass layer 124 (particularly near the boundary surface of the semiconductor substrate) (preliminary evaluation). . Further, the glass composites of Examples 1 to 11 and Comparative Examples 1 to 6 were applied onto a semiconductor substrate having a 10 mm angle to form a layer composed of a glass composite for semiconductor junction protection, and the semiconductor junction was protected by firing. A layer composed of a glass composite is used to form a glass layer, and then it is observed whether or not bubbles are generated inside the glass layer (particularly near the boundary surface of the semiconductor substrate) (official evaluation)

FIG. 6 is a view for explaining bubbles B generated inside the glass layer 124 in the preliminary evaluation. Fig. 6(a) is a cross-sectional view of the semiconductor device when bubble b is not generated, and Fig. 6(b) is a cross-sectional view of the semiconductor device when bubble b is generated. FIG. 7 is a photograph for explaining bubbles b generated inside the glass layer 124 in the formal evaluation. Fig. 7(a) is a magnified photograph showing a boundary surface between a semiconductor substrate and a glass layer when no bubble b is generated, and Fig. 7(b) is an enlarged view showing a boundary surface between a semiconductor substrate and a glass layer when bubble b is generated. photo. It is clear from the experimental results that the results of the preliminary evaluation have a good correspondence with the evaluation results of the present invention. In addition, in the formal evaluation, when bubbles having a diameter of 50 μm or more were not generated inside the glass layer, it was evaluated as “○”, and when 1 to 20 bubbles having a diameter of 50 μm or more were generated inside the glass layer, it was evaluated as “ △" (indicating "not very good") was evaluated as "x" when 20 or more bubbles having a diameter of 50 μm or more were generated inside the glass layer.

Figure 8 is a cross-sectional TEM photograph of a portion including a semiconductor substrate and a glass layer. It is clear from Fig. 8 that an insulating layer (layer thickness: about 20 nm) exists between the semiconductor substrate and the glass layer.

(7) Evaluation project 7 (with or without the addition of nickel oxide)

One of the objects of the present invention is to enable a defoaming component such as nickel oxide to be added or added in a small amount (2.0 mol% or less) in a process of forming a glass layer by firing a layer composed of a glass composite. The phenomenon that bubbles may be generated from the boundary surface of the semiconductor substrate and the glass layer is suppressed. Therefore, when nickel oxide is not added, it is evaluated as "?" (indicating "very good"), and when nickel oxide is added but the amount of addition is 2.0 mol% or less, it is evaluated as "○", when nickel oxide When the amount added was more than 2.0 mol%, it was evaluated as "x".

(8) Evaluation project 8 (reverse leakage current)

A semiconductor device (pn diode) is manufactured by the same method as the method of manufacturing a semiconductor device according to the first embodiment, and a reverse current of the manufactured semiconductor device is measured. Figure 9 is a graph showing the reverse current in the embodiment. 9(a) is a view showing reverse leakage current in the first embodiment, and FIG. 9(b) is a view showing reverse leakage current in the comparative example 5. As a result, when a reverse voltage VR of 600 V was applied, if the reverse leakage current was 1 μA or less, it was evaluated as “○”, and if the reverse leakage current IR exceeded 1 μA, it was evaluated as “×”.

(9) Evaluation project 9 (high temperature reverse bias tolerance)

The semiconductor device manufactured by the method similar to the method for manufacturing a semiconductor device according to the first embodiment is molded into a resin-molded semiconductor device, and the resin-packaged semiconductor device is subjected to a high-temperature reverse bias test to measure the high temperature. Toward bias tolerance. The high-temperature reverse bias tolerance was measured by applying a sample to a constant temperature bath and a high-temperature bias tester set to a temperature of 175 ° C, and applying a potential of 600 V between the anode electrode and the cathode electrode. A total of 20 hours was measured and a reverse current was measured every 5 minutes.

Fig. 10 is a graph showing the results of a high temperature reverse bias test. In Fig. 10, the solid line indicates the reverse leakage current of the sample prepared using the glass composite of Example 1, and the broken line indicates the reverse leakage current of the sample prepared using the glass composite of Comparative Example 1. As shown in FIG. 10, for the sample prepared using the glass composite of Comparative Example 1, the reverse leakage current increased as the temperature rised after the start of the high-temperature reverse bias test, and then, as time passed The reverse leakage current continues to increase, and the value of the predetermined reverse leakage current is reached 3 hours after the start of the high temperature reverse bias test, thus ending the high temperature reverse bias test. On the other hand, it is also clear that for the sample prepared using the glass composite of Example 1, the reverse leakage current increases as the temperature rises after the start of the high-temperature reverse bias test, and then the reverse leakage current is almost No longer increase. Thus, if the reverse leakage current increases as the temperature rises after the high-temperature reverse bias test starts, and then the reverse leakage current hardly increases, the evaluation is "○", if the reverse bias is at high temperature. Reverse leakage current after the start of the pressure test As the temperature increases, the reverse leakage current continues to increase with the passage of time, and is evaluated as "x".

(10) Evaluation project 10 (with or without diffusion from B in the glass layer)

A glass composite layer was formed by electrophoresis on the surface of an n-type germanium substrate (impurity concentration: 2.0 × 10 ¹⁴ cm ^-3 ), and then fired in wet oxygen at 800 ° C to form a glass layer. As the glass composite, the glass composite of Example 1 and the glass composite of Comparative Example 6 were used. Thereafter, the glass layer is removed by hydrofluoric acid to expose the surface of the n-type germanium substrate. Thereafter, the SRP distribution (Spreading Resistance Profiler) was measured in the depth direction from the surface of the n-type crucible in the depth direction using an extended resistance measuring device (manufactured by SSM Corporation, Japan), and the impurity concentration was calculated from the obtained expansion resistance.

Fig. 11 is a view showing an impurity concentration distribution in the depth direction from the surface of the crucible. In Fig. 11, the solid line indicates the impurity concentration distribution of the sample prepared using the glass composite of Example 1, and the broken line indicates the impurity concentration distribution of the sample prepared using the glass composite of Comparative Example 6. It is clear from Fig. 11 that a p-type impurity layer having a depth of 10 nm was formed on the surface of the crucible of the sample prepared using the glass composite of Comparative Example 6. This means that in a glass composite containing both B (boron) and an alkali metal, B (boron) diffuses from the glass layer into the crucible during the firing of the glass composite. On the other hand, it was also confirmed that the p-type impurity layer was not formed on the surface of the crucible of the sample prepared using the glass composite of Example 1. This means that in a glass composite not containing an alkali metal, even in the case of containing, for example, B (boron), B (boron) does not diffuse from the glass layer into the crucible during the firing of the glass composite. . Therefore, when the glass composite is a glass composite which contains B (boron) but does not diffuse from the glass layer into the crucible during the firing of the glass composite, it is evaluated as "○", when When B (boron) was diffused from the glass layer to the glass composite in the crucible during the firing of the composite, it was evaluated as "x".

(10) Comprehensive evaluation

When there is no "△" or "X" in the above evaluation items 1 to 10, the evaluation is "○"; when there is at least one "△" or "×" in each evaluation, it is evaluated as "X".

3. Evaluation results

As is clear from Fig. 5, the glass composites of Comparative Examples 1 to 6 all had an evaluation of "x" in at least one evaluation project, and thus a total evaluation of "x" was obtained. That is, Comparative Example 1 obtained an evaluation of "X" in the evaluation projects 1, 9. Further, in Comparative Example 2, an evaluation of "X" was obtained in Evaluation Project 3. Further, in Comparative Example 3, an evaluation of "x" was obtained in Evaluation Project 6. Further, in Comparative Example 4, evaluation of "x" was obtained in Evaluation Items 5, 7. Further, in Comparative Example 5, an evaluation of "x" was obtained in Evaluation Project 8. Further, Comparative Example 6 was evaluated as "X" in Evaluation Items 8,10.

On the other hand, Example 1 was evaluated as "○" in all evaluation items (evaluation items 1 to 10), and Examples 2 to 11 were evaluated as "○" or "◎ in evaluation items 1 to 9". ". As a result, the method of manufacturing the semiconductor device according to the first to eleventh embodiments is a method of manufacturing a semiconductor device capable of producing a semiconductor device using a lead-free glass material and satisfying (a) a suitable one. (b) is resistant to chemicals used in the process; (c) has a linear expansion coefficient close to the linear expansion coefficient of the crucible in order to prevent bending of the wafer in the process ( In particular, the average linear expansion coefficient at 50 ° C to 550 ° C is close to the linear expansion coefficient of 矽; and (d) all conditions such as excellent insulation, and further, the following conditions are satisfied: (e) in the process of vitrification (a) in the process of firing a layer composed of a glass composite by electrophoresis, suppressing the occurrence of bubbles from the boundary surface with the semiconductor substrate, thereby suppressing the reverse withstand voltage characteristics of the semiconductor device. The occurrence of deterioration occurs, (g) as a result, the amount of NiO (nickel oxide) can be suppressed to 2.0 mol%. Below; (h) the reverse leakage current is low; and (i) has a high high temperature reverse bias tolerance.

In addition, as shown in FIG. 9(b), the semiconductor device manufactured by the method for manufacturing a semiconductor device according to the fifth embodiment has a higher reverse current than the semiconductor device manufactured by the method for manufacturing a semiconductor device according to the first embodiment. When the reverse voltage VR of 600 V is applied, the reverse current is about 4 μA, which is a level that can be sufficiently used depending on the application.

Although the method of manufacturing the semiconductor device and the semiconductor device of the present invention have been described above based on the above embodiments, the present invention is not limited thereto, and may be implemented without departing from the scope of the invention. For example, the following modifications may be made. .

(1) In the above embodiments, the glass layer for forming a semiconductor joint for protection according to the first embodiment is used. However, the present invention is not limited thereto, and NiO-free (nickel oxide) may be used. The glass composite for semiconductor junction protection forms a glass layer.

(2) In each of the above embodiments, the glass layer is formed by electrophoresis, but the invention is not limited thereto. For example, the glass layer may be formed by a spin-coat method, a screen printing method, or another glass layer forming method.

(3) In each of the above embodiments, the thickness of the insulating layer is set to be in the range of 5 nm to 60 nm, and the glass layer is formed by electrophoresis, but the invention is not limited thereto. The thickness of the insulating layer may be set in the range of 5 nm to 100 nm and the glass layer may be formed by another glass layer forming method. In this case, when the thickness of the insulating layer is less than 5 nm, there may be a case where the effect of the reverse current reduction cannot be obtained. On the other hand, when the thickness of the insulating layer exceeds 100 nm, there may be a possibility of forming a high-quality glass composite by a spin coating method, a screen printing method, or another glass layer forming method in the subsequent glass layer forming process. The case of the layer formed by the object.

(4) In the above embodiments, the insulating layer composed of the tantalum oxide film is formed by a thermal oxidation method using dry oxygen (DryO ₂ ), but the present invention is not limited thereto. For example, an insulating layer composed of a tantalum oxide film may be formed by a thermal oxidation method using dry oxygen and nitrogen (DryO ₂ + N ₂ ), or may be formed by a thermal oxidation method using wet oxygen (WetO ₂ ). An insulating layer made of a tantalum oxide film may be formed by a thermal oxidation method using wet oxygen and nitrogen (WetO ₂ + N ₂ ) to form an insulating layer made of a tantalum oxide film. Further, an insulating layer made of a tantalum oxide film may be formed by CVD. Further, an insulating layer other than the tantalum oxide film (for example, an insulating layer made of a tantalum nitride film) may be formed.

(5) In the above embodiments, the present invention has been described by taking a diode (a mesa-type pn diode or a planar pn diode) as an example, but the present invention is not limited thereto. All semiconductor devices exposed by the pn junction (for example, thyristors, power MOSFETs, IGBTs, etc.) are suitable for use in the present invention.

(6) In the above embodiments, the substrate made of tantalum is used as the semiconductor substrate, but the invention is not limited thereto. For example, a semiconductor substrate such as a SiC substrate, a GaN substrate, or a GaO substrate may be used.

(7) In the method of manufacturing a semiconductor device and the semiconductor device of the present invention, it is preferable to use a glass composite which is difficult to crystallize during the firing of the glass composite layer. In this way, it is possible to manufacture a stable semiconductor device having a low reverse leakage current. In this regard, the present invention is described in Japanese Laid-Open Patent Publication No. SHO-63-117929, the disclosure of which is incorporated herein by reference. The technology is different.

(8) In the method of manufacturing a semiconductor device and the semiconductor device of the present invention, it is preferable to use a material which does not substantially contain Bi. In this way, during the firing of the glass composite layer Since the glass layer is difficult to crystallize, it is possible to manufacture a stable semiconductor device having a low reverse leakage current. In this regard, the present invention is different from the technique described in Japanese Laid-Open Patent Publication No. 2005-525287, which uses a raw material containing Bi.

(9) In the method of manufacturing a semiconductor device and the semiconductor device of the present invention, it is preferable to use a material that does not substantially contain Cu. As described above, since the glass layer is hard to be crystallized during the firing of the glass composite layer, it is possible to manufacture a stable semiconductor device having a low reverse leakage current. In this regard, the present invention is different from the technique described in Japanese Laid-Open Patent Publication No. 2001-287984, which uses a raw material containing Cu.

(10) In the method of manufacturing a semiconductor device and the semiconductor device of the present invention, a material that does not substantially contain Li and Pb is used. In this regard, the present invention is different from the technique described in Japanese Laid-Open Patent Publication No. 2002-16272, which uses a raw material containing Li and Pb.

In the case of the glass layer for passivation, zinc-based glass (glass having the highest content of zinc oxide) is used as described in Japanese Laid-Open Patent Publication No. 53-36463. However, the zinc-based glass has low chemical resistance (refer to Comparative Example 2 of the above embodiment), and is not easily applied to the method of manufacturing a semiconductor device and the semiconductor device of the present invention.

(12) In the method of manufacturing a semiconductor device and the semiconductor device of the present invention, it is preferable to use a material which does not substantially contain P. Thus, P (phosphorus) is prevented from diffusing from the glass layer to the semiconductor substrate during the firing of the glass composite layer, so that a highly reliable semiconductor device can be manufactured.

Claims (26)

A method of manufacturing a semiconductor device, comprising: a first step of preparing a semiconductor element having a pn junction exposed portion having a pn junction exposed; a second step of forming an insulating layer covering the exposed portion of the pn junction; and a third step of After forming a layer made of a glass composite for semiconductor junction protection on the insulating layer, a layer made of the glass composite for semiconductor junction protection is fired, and a glass layer is formed on the insulating layer, wherein The glass composite for protecting a semiconductor junction is composed of glass fine particles obtained by melting a raw material, and the raw material contains at least SiO ₂ , Al ₂ O ₃ , B ₂ O ₃ , ZnO and an oxide containing at least two kinds of alkaline earth metals of CaO, MgO, and BaO, and substantially containing no Pb, As, Sb, Li, Na, and K, and the glass composite for semiconductor junction protection does not contain the raw material any one component as a filler, the content of the glass protecting a semiconductor junction composite SiO ₂ in the range of 41.1mol% ~ 61.1mol%, Al ₂ O ₃ content is at 7.4mol% ~ 17.4mol% of Inner circle, the content of B ₂ O ₃ in the range of 5.8mol% ~ 15.8mol%, the content of ZnO is in the range of 3.0mol% ~ 24.8mol%, an alkaline earth metal oxide content in 5.5mol% ~ 15.5mol %In the range. The method of manufacturing a semiconductor device according to claim 1, wherein the glass composite for protecting a semiconductor junction does not substantially contain a polyvalent element as a defoaming agent. The method of manufacturing a semiconductor device according to claim 2, wherein the multivalent element comprises V, Mn, Sn, Ce, Nb, and Ta. The method of manufacturing a semiconductor device according to any one of claims 1 to 3, characterized in that Wherein, the raw material does not substantially contain P. The method of manufacturing a semiconductor device according to any one of claims 1 to 3, wherein the raw material does not substantially contain Bi. The method of manufacturing a semiconductor device according to any one of claims 1 to 3, wherein the glass composite for protecting a semiconductor junction does not contain an organic binder. The method of manufacturing a semiconductor device according to any one of claims 1 to 3, wherein in the third step, the semiconductor bonding protective glass is fired at a temperature of 900 ° C or lower. A layer composed of a composite. The method of manufacturing a semiconductor device according to any one of claims 1 to 3, wherein the insulating layer is made of tantalum oxide. The method of manufacturing a semiconductor device according to any one of claims 1 to 3, wherein in the second step, the insulating layer is formed to have a thickness in a range of 5 nm to 100 nm. The method of manufacturing a semiconductor device according to any one of claims 1 to 3, wherein in the third step, a layer made of the glass composite is formed by an electrophoresis method. The method of manufacturing a semiconductor device according to claim 10, wherein in the second step, the insulating layer is formed to have a thickness in a range of 5 nm to 60 nm. The method of manufacturing a semiconductor device according to any one of claims 1 to 3, wherein the first step includes a step of preparing a semiconductor substrate having a pn junction parallel to a main surface; a surface of one side of the semiconductor substrate is formed to have a depth exceeding a channel of the pn junction, and a step of forming the exposed portion of the pn junction is formed on an inner surface of the channel, and the second process is included in the channel Forming the insulation covering the exposed portion of the pn junction The step of forming a layer includes the step of forming the glass layer on the insulating layer in the third step. The method of manufacturing a semiconductor device according to claim 12, wherein in the second step, the insulating layer is formed by a thermal oxidation method. The method of manufacturing a semiconductor device according to claim 12, wherein in the second step, the insulating layer is formed by a deposition method. The method of manufacturing a semiconductor device according to any one of claims 1 to 3, wherein the first step includes a step of forming the pn junction exposed portion on a surface of the semiconductor substrate, and the second step includes The step of forming the insulating layer covering the exposed portion of the pn junction in the surface of the semiconductor substrate, and the step of forming the glass layer on the insulating layer in the third step. The method of manufacturing a semiconductor device according to claim 15, wherein in the second step, the insulating layer is formed by a thermal oxidation method. The method of manufacturing a semiconductor device according to claim 15, wherein in the second step, the insulating layer is formed by a deposition method. The method of manufacturing a semiconductor device according to claim 1, wherein the glass composite in the third step does not form crystals during firing to form a glass layer. A method of manufacturing a semiconductor device, comprising: a first step of preparing a semiconductor element having a pn junction exposed portion having a pn junction exposed; a second step of forming an insulating layer covering the exposed portion of the pn junction; and a third step of After forming a layer made of a glass composite for semiconductor junction protection on the insulating layer, a layer made of the glass composite for semiconductor junction protection is fired, and a glass layer is formed on the insulating layer, wherein The glass composite for protecting a semiconductor junction is composed of glass fine particles obtained by melting a raw material, and the raw material contains at least SiO ₂ , Al ₂ O ₃ , B ₂ O ₃ , ZnO and an oxide containing at least two kinds of alkaline earth metals of CaO, MgO, and BaO, and substantially containing no Pb, As, Sb, Li, Na, and K, and the glass composite for semiconductor junction protection does not contain the raw material Any of the components as a filler, the semiconductor bonding protective glass composite has a SiO ₂ content of 49.5 mol% to 64.3 mol%, and a B ₂ O ₃ content of 8.4 mol% to 17.9 mol%. Within the range, the content of Al ₂ O ₃ is in the range of 3.7 mol% to 14.8 mol%, the content of ZnO is in the range of 3.9 mol% to 14.2 mol%, and the content of oxide of alkaline earth metal is in the range of 7.4 mol% to 12.9 mol. %In the range. The method of manufacturing a semiconductor device according to claim 19, wherein the glass composite in the third step does not form crystals during firing to form a glass layer. A semiconductor device comprising: a semiconductor element having a pn junction exposed portion exposed by a pn junction; an insulating layer formed to cover the pn junction exposed portion; and a glass layer formed on the insulating layer, the glass layer It is formed by forming a layer made of a glass composite for semiconductor junction protection on the insulating layer, and then firing the layer made of the glass composite for semiconductor junction protection, wherein the semiconductor junction The glass composite for protection is composed of glass fine particles obtained by melting a molten material containing at least SiO ₂ , Al ₂ O ₃ , B ₂ O ₃ , ZnO, and CaO. An oxide of at least two alkaline earth metals of MgO and BaO, and substantially free of Pb, As, Sb, Li, Na, and K, and the glass composite for semiconductor junction protection does not contain any one of the raw materials. In the filler, the content of SiO ₂ in the glass composite for semiconductor junction protection is in the range of 41.1 mol% to 61.1 mol%, and the content of Al ₂ O ₃ is in the range of 7.4 mol% to 17.4 mol%, B ₂ O ₃ content is 5 In the range of .8 mol% to 15.8 mol%, the content of ZnO is in the range of 3.0 mol% to 24.8 mol%, and the content of the oxide of the alkaline earth metal is in the range of 5.5 mol% to 15.5 mol%. The semiconductor device according to claim 21, wherein the raw material does not substantially contain Bi. The semiconductor device according to claim 21, wherein the glass layer does not contain crystals. A semiconductor device comprising: a semiconductor element having a pn junction exposed portion exposed by a pn junction; an insulating layer formed to cover the pn junction exposed portion; and a glass layer formed on the insulating layer, the glass layer It is formed by forming a layer made of a glass composite for semiconductor junction protection on the insulating layer, and then firing the layer made of the glass composite for semiconductor junction protection, wherein the semiconductor junction The glass composite for protection is composed of glass fine particles obtained by melting a molten material containing at least SiO ₂ , Al ₂ O ₃ , B ₂ O ₃ , ZnO, and CaO. An oxide of at least two alkaline earth metals of MgO and BaO, and substantially free of Pb, As, Sb, Li, Na, and K, and the glass composite for semiconductor junction protection does not contain any one of the raw materials. In the filler, the content of SiO ₂ in the glass composite for semiconductor junction protection is in the range of 49.5 mol% to 64.3 mol%, and the content of B ₂ O ₃ is in the range of 8.4 mol% to 17.9 mol%, and Al ₂ O ₃ content in 3 In the range of .7mol% to 14.8mol%, the content of ZnO is in the range of 3.9mol% to 14.2mol%, and the content of oxides of alkaline earth metals is in the range of 7.4mol% to 12.9mol%. The semiconductor device according to claim 24, wherein the raw material does not substantially contain Bi. The semiconductor device according to claim 24, wherein the glass layer does not contain crystals.