JPH11162909A - Method for manufacturing semiconductor wafer - Google Patents

Abstract

(57) [Summary] [Object] To provide a method of manufacturing a semiconductor wafer capable of reducing processing time and material cost. SOLUTION: In a method of manufacturing a semiconductor wafer, a sliced semiconductor wafer is subjected to diffusion processing and then finished to a predetermined thickness to manufacture a substrate wafer, wherein the diffusion processing is performed on a surface of one semiconductor wafer 20. This is performed on the entire back surface, and by slicing the front and back surfaces of the one semiconductor wafer after the diffusion processing into two parts, one surface is a diffusion processing surface and the other surface is a non-diffusion processing surface. This is a manufacturing method in which two semiconductor wafers are formed and then finished to a predetermined thickness.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor wafer manufacturing method for manufacturing a semiconductor wafer with good yield by reducing the surface polishing amount of a diffusion wafer after a diffusion process.

[0002]

2. Description of the Related Art Conventionally, when manufacturing a semiconductor wafer,
As shown in FIG. 6, a step S1 for slicing a processing wafer, a step S2 for chamfering, a step S3 for lapping,
A semiconductor wafer (hereinafter, referred to as a wafer) has been manufactured by finishing in a mirror polishing step S8 through an etching step S4, a cleaning step S5, a diffusion processing step S6, and a grinding step S7. In addition, since both surfaces of the wafer are diffused in the diffusion processing step, it is common practice to perform grinding and mirror finishing at the finishing stage, and process one surface of the wafer until it reaches a finished thickness.

[0003]

However, in the above-mentioned conventional method, after a wafer subjected to a slicing step or the like is subjected to diffusion processing, one side must be polished to a finished thickness in a grinding step or a mirror polishing step. However, there is a problem that the processing cost for this polishing is increased, the processing time is increased, and the material cost is increased.

An object of the present invention is to provide a method for manufacturing a semiconductor wafer which solves the above problems.

[0005]

According to a first aspect of the present invention, there is provided a method of manufacturing a semiconductor wafer, wherein a single sliced semiconductor wafer is subjected to a diffusion treatment and then finished to a predetermined thickness to manufacture a substrate wafer. In the method, the diffusion process is performed on the entire front and back surfaces of one semiconductor wafer, and by slicing the front and back surfaces of the one semiconductor wafer after the diffusion process into two parts, This is a manufacturing method in which two semiconductor wafers, one surface of which is a diffusion-treated surface and the other surface of which is a non-diffusion-treated surface, are formed and then finished to a predetermined thickness. Therefore, by slicing the semiconductor wafer having been subjected to the diffusion treatment into two parts while leaving, for example, a finished thickness and a polishing allowance, the amount of polishing of the diffused semiconductor wafer can be reduced, and the polishing time and material cost can be reduced.

According to a second aspect of the present invention, there is provided a method of manufacturing a semiconductor wafer in which a single sliced semiconductor wafer is subjected to a diffusion treatment and then finished to a predetermined thickness.
One semiconductor wafer that has been subjected to diffusion processing is cut by a cutting device.
The slice is divided into two parts. In the two-division slice, an adsorbing member that adsorbs and supports the semiconductor wafer is cut by the cutting device, the semiconductor wafer is adsorbed and supported on the cut surface, and the cut surface is set as a reference surface. The method further comprises slicing by the cutting device and thereafter finishing to a predetermined thickness. Therefore, since the semiconductor wafer is sliced using the cut surface as a reference surface, the thickness of the cut wafer can be made uniform, and the first wafer can be sliced.
Similarly to the invention, by slicing the semiconductor wafer subjected to the diffusion treatment into, for example, two divisions while leaving a finished thickness and a polishing allowance, the polishing amount of the diffusion semiconductor wafer can be reduced,
The polishing time can be shortened and the raw material cost can be reduced.

[0007] A manufacturing method according to a third invention of the present application is a method for manufacturing a semiconductor wafer in which one sliced semiconductor wafer is subjected to a diffusion treatment and then finished to a predetermined thickness.
After laminating a plurality of diffusion-processed semiconductor wafers and bonding them, the semiconductor wafer integrated by this bonding is sliced by a cutting device,
In this slicing, the respective cutting blades of the cutting device are positioned corresponding to the individual semiconductor wafers in the semiconductor wafer integrated by the bonding, and sliced at a time by the cutting device, whereby the bonding is performed. Each of the semiconductor wafers is sliced into two slices.
This is a manufacturing method for finishing a divided semiconductor wafer to a predetermined thickness. Therefore, a large number of semiconductor wafers can be simultaneously accurately divided and sliced, so that the polishing time and the material cost can be reduced, and the number of manufacturing steps can be further reduced.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiment.

In this embodiment, a wafer is manufactured according to the procedure of the flowchart shown in FIG. That is, in the cutting step S11, the single crystal silicon ingot is sliced into a thicker wafer, and the peripheral edge chamfering process of the wafer cut in the chamfering step S12 is performed. Next, the surface is polished in a lapping step S13, the pre-processed surface of the wafer surface is removed in an etching step S14, and a smooth surface is obtained. S16 is performed. The diffusion process S17 is performed while heating the wafer in a predetermined gas. Then, in a division cutting step S17, the diffusion wafer is sliced into two parts so as to have a thickness close to a predetermined thickness, and then the wafer is polished in a polishing step S18. Is ground to a predetermined thickness, and the surface is polished by mirror polishing, whereby the diffusion wafer is finished.

In the division cutting step S17, the cutting device 10 shown in FIG. 2 is used. This cutting device 10
A hemispherical housing 12 is fixed on a rotating shaft 11, and a support blade 1 fixed to a peripheral portion of the housing 12 is provided.
An inner peripheral blade 14 having a predetermined inner diameter is attached to 3, and the inner peripheral blade 14 is rotated by rotation of the rotating shaft 11.

As shown by arrows A and B in FIG. 2, a support member 15 connected to an indexing device so as to be able to move vertically and horizontally is provided above the center of the housing 12. . On the lower surface of the support member 15, a columnar adsorption member 16 made of carbon is fixed. This suction member 16
Is embedded with a Seaflex tube 17 and is connected to a suction device through a tube 18.

In the dividing and cutting step S17, the wafer 20 after the diffusion process is sucked and held on the lower surface of the suction member 16 by suction of the suction device. On the other hand, the wafer 20 is aligned. At the time of cutting, the rotating shaft 11 is rotated to rotate the inner peripheral blade 14.
Is rotated, the wafer 20 is sliced while horizontally moving the wafer 20 by the indexing mechanism, and the inner peripheral blade 1 is sliced.
4, the processing margin of the lower end side (one side) of the wafer 20 in the figure is cut off, and the thickness of the sucked wafer 20 is formed to a thickness close to the target thickness. Then, the processing allowance is a thickness leaving the finished thickness and the polishing allowance.

Further, as described above, the cut wafer 20 is polished to a target thickness in the polishing step S18, and is finished by mirror polishing.

Therefore, in the divisional cutting step, since the slice is sliced so as to have a thickness close to the target thickness, the processing allowance in the next polishing step is reduced, the polishing time is shortened, and the cut wafer is cut. By recycling, waste of raw material costs can be reduced.

Further, at the time of the division cutting, FIG.
This can be done by setting a reference plane as shown in FIG. In this case, prior to the wafer cutting, the lower end side of the suction member 16 is cut by the inner peripheral blade 14 as shown in FIG. As a result, the cut surface becomes parallel to the inner peripheral blade 14, so that the wafer 20 is suctioned to the reference surface with this as the reference surface, and the wafer 20 is cut. Therefore, the thickness of the wafer 20 to be cut can be made uniform. In this case, the return amount z by the indexing mechanism is z = (χ−y) / 2, which is the thickness of the two-piece wafer. Χ is the thickness of the wafer, and y is the blade thickness (including the cutting allowance).

The devices 22 and 24 shown in FIGS. 4 and 5 can be used as the cutting device in the division cutting step.

The cutting device 22 shown in FIGS.
As shown in FIGS. 2A and 2B, a plurality of non-contact capacitive sensors 23 are attached to the lower surface of the wafer 20 adsorbed by the adsorbing member 16 and the inner peripheral blade 14 is attached to the inner peripheral blade 14 using these sensors 23. The parallelism is adjusted by the crystal axis alignment mechanism in the directions indicated by arrows X and Y in the figure so as to be parallel, and the distance between the inner peripheral blade and the diffusion wafer is measured by the sensor 23. The slice position is set and divided, and the accuracy of the wafer thickness at the time of slicing can be improved.

The cutting device 24 shown in FIGS.
Are an adhesive gantry 25 for horizontally stacking a plurality of wafers 20 subjected to diffusion processing and bonding them together, and a gantry 25 for slicing the overlapped wafers 20 at one time.
A plurality of wires (straight blades) 26 disposed above,
A non-contact type eddy current sensor 28 installed parallel to the surface of the wafer 20, which is supported by the fixing jig 27 on one end side of the wafer 5, and a positioning mechanism (not shown) for aligning a plurality of wires 26. The plurality of wafers 20 are sliced at a time by lowering the plurality of wires 26.

That is, in this embodiment, after a plurality of semiconductor wafers subjected to diffusion processing are laminated and bonded,
In slicing the semiconductor wafer integrated by the bonding by the cutting device, the respective cutting blades of the cutting device are positioned in correspondence with the individual semiconductor wafers in the semiconductor wafer integrated by the bonding. Each of the bonded semiconductor wafers is sliced into two by slicing at one time by the cutting device, and thereafter, the divided semiconductor wafers are finished to a predetermined thickness.

In this cutting apparatus, a large number of wafers are cut in two at a time by the sensor 28 which can adjust the cutting movement surface of the wire 26 and the wafer splitting position in parallel, so that the thickness accuracy of each wafer 20 can be improved. In addition, the working time can be reduced.

As a result of the present inventors' tests on the case of using the inner peripheral blade and the case of using the straight blade, as shown in Table 1, the machining allowance in each step was obtained as shown in the table. That is, when the target thickness of the wafer is 300 μm, the total processing allowance from cutting to polishing is 5 per sheet according to the conventional method.
While it is 85 μm, it is 422.5 μm per sheet according to the two-part cutting by the inner peripheral teeth, and 297.5 μm per sheet according to the straight blade, which greatly reduces the machining allowance as compared with the conventional case. I was able to.

[0022]

[Table 1]

[0023]

As described above, in the manufacturing method according to the first aspect of the present invention, a semiconductor wafer is manufactured by diffusing a single sliced semiconductor wafer and finishing it to a predetermined thickness to manufacture a substrate wafer. In the manufacturing method, the diffusion treatment is performed on the entire front and back surfaces of one semiconductor wafer, and by slicing the front and back surfaces of the one semiconductor wafer into two after the diffusion treatment. This is a manufacturing method of forming two semiconductor wafers, one surface of which is a diffusion-treated surface and the other surface of which is a non-diffusion-treated surface, and thereafter finishing the semiconductor wafer to a predetermined thickness. By slicing the semiconductor wafer into two parts while leaving the polishing allowance, the polishing amount of the diffusion semiconductor wafer can be reduced, so that the polishing time and the material cost can be reduced.

Further, the manufacturing method according to the second invention of the present application comprises:
In a method for manufacturing a semiconductor wafer in which a single sliced semiconductor wafer is subjected to diffusion processing and then finished to a predetermined thickness, one diffusion-processed semiconductor wafer is sliced into two parts by a cutting device. In slicing into two parts, the suction member that suctions and supports the semiconductor wafer is cut by the cutting device, the semiconductor wafer is suctioned and supported on the cut surface, and the slice is further sliced by the cutting device using the cut surface as a reference surface, and This is a manufacturing method in which the semiconductor wafer is sliced with the cut surface as a reference surface, so that the thickness of the wafer to be cut can be made uniform, and the diffusion-processed semiconductor can be finished. By slicing the wafer into two parts, for example, leaving the finished thickness and polishing allowance, the diffusion semiconductor wafer Migakuryou can reduce, it is possible to reduce the shortening and raw material cost of the polishing time.

Further, the manufacturing method according to the third invention of the present application is:
In a method for manufacturing a semiconductor wafer in which a single sliced semiconductor wafer is subjected to diffusion processing and then finished to a predetermined thickness, a plurality of diffusion-processed semiconductor wafers are stacked and bonded, and then bonded to form an integrated semiconductor wafer. A semiconductor device is sliced by a cutting device, and in this slicing, each cutting blade of the cutting device is
Positioning is performed in accordance with the individual semiconductor wafers in the semiconductor wafer integrated by the bonding,
This is a manufacturing method of slicing each of the bonded semiconductor wafers into two parts by slicing at one time by the cutting device, and thereafter finishing the divided semiconductor wafers to a predetermined thickness. It is possible to accurately divide the slice, to shorten the polishing time and reduce the raw material cost, and to further reduce the number of manufacturing steps.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a semiconductor wafer manufacturing process according to a first embodiment of the present invention.

FIG. 2 is a schematic view of a split cutting device according to a first embodiment of the present invention.

3 (a) and 3 (b) are schematic diagrams illustrating the operation of a split cutting device according to a second embodiment of the present invention.

FIGS. 4A and 4B are schematic views of a dividing and cutting apparatus, and FIG. 4B is a plan view showing a sensor arrangement structure according to a third embodiment of the present invention.

5A and 5B are front views of a split cutting device, and FIG. 5B is a side view of the split cutting device, according to a fourth embodiment of the present invention.

FIG. 6 is a flowchart showing a conventional manufacturing process.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Cutting device 16 Adsorption member 20 Semiconductor wafer 22 Cutting device 24 Cutting device S16 Diffusion processing process

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tetsujiro Yoshiharu 1 Higashihama-cho, Amagasaki City, Hyogo Prefecture Osaka Titanium Manufacturing Co., Ltd.

Claims (3)

[Claims] A semiconductor wafer manufacturing method for manufacturing a substrate wafer by subjecting a sliced semiconductor wafer to diffusion processing and then finishing the semiconductor wafer to a predetermined thickness, wherein the diffusion processing is performed on a surface of one semiconductor wafer. This is performed on the entire back surface, and by slicing the front and back surfaces of the one semiconductor wafer after the diffusion processing into two parts, one surface is a diffusion processing surface and the other surface is a non-diffusion processing surface. A method for manufacturing a semiconductor wafer, comprising forming two semiconductor wafers and then finishing to a predetermined thickness. 2. A sliced semiconductor wafer,
In a method for manufacturing a semiconductor wafer which is finished to a predetermined thickness after the diffusion processing, a single semiconductor wafer subjected to the diffusion processing is cut by a cutting device.
The slice is divided into two parts. In the two-division slice, an adsorbing member that adsorbs and supports the semiconductor wafer is cut by the cutting device, the semiconductor wafer is adsorbed and supported on the cut surface, and the cut surface is set as a reference surface. And further slicing by the cutting device and thereafter finishing to a predetermined thickness. 3. A semiconductor wafer obtained by slicing one semiconductor wafer,
In the method for manufacturing a semiconductor wafer to be finished to a predetermined thickness after the diffusion treatment, a plurality of semiconductor wafers subjected to the diffusion treatment are laminated and bonded, and the semiconductor wafer integrated by the bonding is cut by a cutting device. Is to slice,
In this slicing, the respective cutting blades of the cutting device are positioned corresponding to the individual semiconductor wafers in the semiconductor wafer integrated by the bonding, and sliced at a time by the cutting device, whereby the bonding is performed. Each of the semiconductor wafers is sliced into two slices.
A method for manufacturing a semiconductor wafer, comprising finishing the divided semiconductor wafer to a predetermined thickness.