KR20070082786A - Semiconductor manufacturing equipment - Google Patents

Abstract

Semiconductor fabricating equipment is provided to completely remove a native oxide layer formed on a semiconductor substrate by enabling precise management of a cleaning process. A semiconductor substrate is received in a process chamber(110). Reaction gas for processing the semiconductor substrate is introduced into a gas introduction line(115) connected to the process chamber. Gas in the process chamber and reaction byproducts generated in the process chamber are exhausted through an exhaust line(116) connected to the process chamber. The inside of the process chamber is heated by a heater. A guide bar(118) penetrates the process chamber to be extended to the periphery of the semiconductor substrate received in the process chamber. A thermocouple measures the temperature of the periphery of the semiconductor substrate, inserted into the guide bar. The reaction gas introduced into the gas introduction line can be distributed in various directions of the chamber by a gas distribution plate installed in the process chamber.

Description

Semiconductor manufacturing equipment

1 is a schematic cross-sectional view illustrating a conventional method for removing a semiconductor native oxide film.

Figure 2 is a schematic diagram showing an embodiment of a semiconductor manufacturing equipment according to the present invention.

3 is a perspective view illustrating a gas distribution plate of FIG. 1 and a guide rod supported thereto.

** Description of the symbols for the main parts of the drawings **

100: semiconductor manufacturing equipment

110: process chamber

111: outer chamber

112: inner chamber

115: gas inflow line

116: exhaust line

118: guide rod

130: load lock chamber

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to equipment for manufacturing semiconductor devices, and more particularly, to semiconductor manufacturing equipment for removing natural oxide films formed on semiconductor substrates such as wafers.

With the trend toward higher integration and miniaturization of semiconductor devices, fine particles such as natural oxide films, organic materials, and metals remaining on semiconductor substrates have a profound effect on product yield and reliability. Therefore, in recent years, the importance of the cleaning process for cleaning such fine particles has emerged greatly.

In general, a natural oxide removal process mainly uses a wet cleaning method in which a semiconductor substrate is placed in a bath containing a predetermined amount of a cleaning liquid and then waits for a predetermined time to remove a natural oxide film present on a wafer.

1 is a schematic cross-sectional view illustrating a conventional process of removing a native oxide film present in a contact hole using a cleaning liquid.

In a typical method of forming a contact hole in a semiconductor device, as shown in FIG. 1, an insulating film 14 and a photosensitive film 16 are sequentially formed on a semiconductor substrate 10 on which a junction 12 is formed by impurity doping. do.

After the contact hole mask is positioned on the photoresist layer 16, the photoresist layer pattern 16 is formed by exposing and developing the photoresist layer 16, and the insulating layer 14 is formed using the photoresist pattern 16 as an etch mask. ) By plasma etching to form a contact hole 19 exposing the semiconductor substrate 10 on the junction portion 12. At this time, in the process of forming the contact hole 19, the semiconductor substrate 10 of the portion where the contact hole 19 is formed is exposed to the outside, and thus a natural oxide film is formed on the semiconductor substrate 10 inside the contact hole 19. 18 can be formed.

Therefore, a cleaning process is performed to remove the native oxide film 18 formed on the semiconductor substrate 10 after the contact hole forming process or before the subsequent process. Here, the cleaning process is performed by wet cleaning the upper surface of the semiconductor substrate 10 using a cleaning solution in which SC1 (Standard Chemical 1) and hydrogen fluoride (HF) are mixed at a constant ratio to remove the natural oxide film.

However, in the conventional method of removing the natural oxide film using the cleaning solution, due to problems such as surface tension on the surface of the semiconductor substrate, the cleaning solution does not sufficiently flow to the bottom surface of the contact hole, that is, the upper part of the junction part, and thus, the inside of the contact hole is prevented. The phenomenon of remaining without removing the natural oxide film completely is occurring. In particular, such a phenomenon occurs more seriously as the diameter of the contact hole becomes smaller as the semiconductor device is highly integrated.

As a result, the natural oxide film remains in the contact hole, resulting in an increase in contact resistance between the conductive material and the junction portion embedded in the contact hole, leading to a sharp drop in yield and reliability of a semiconductor product.

Therefore, recently, the dry cleaning which removes a natural oxide film by inflowing plasma gas etc. into a high temperature chamber is newly used. In this case, the temperature inside the chamber is measured and controlled by forming a hole in one inner wall of the chamber and inserting a thermocouple (also referred to as 'T / C') capable of sensing the temperature therein. have.

However, in the conventional case, since only the ambient temperature inside the chamber is measured through a hole formed in one inner wall of the chamber, the ambient temperature of the semiconductor substrate, which is directly cleaned, is measured. There are many differences in the temperature measured by the thermocouple. Therefore, when the temperature inside the chamber is adjusted based on the temperature measured by the conventional thermocouple, a problem arises in that the temperature of the portion where the actual cleaning is performed cannot be accurately adjusted to a temperature suitable for cleaning, which completely removes the natural oxide film. It can also be a major cause of failure to remove.

Accordingly, the present invention has been made in view of such a problem, and the technical problem to be achieved by the present invention is to provide a semiconductor manufacturing equipment that can accurately measure the temperature of the actual cleaning portion inside the chamber.

The present invention for implementing the above technical problem is a process chamber in which a semiconductor substrate is accommodated therein, a gas inlet line connected to the process chamber and a reaction gas for processing the semiconductor substrate is introduced, and in the process chamber An exhaust line connected to and exhausting gas inside the process chamber and reaction by-products generated in the process chamber, a heater for heating the inside of the process chamber, and the accommodating inside the process chamber through the process chamber. The guide rod extends to the periphery of the semiconductor substrate, and a thermocouple inserted into the guide rod to measure the temperature of the periphery of the semiconductor substrate.

In this case, the guide rod may penetrate one side of the process chamber to extend to the periphery of the semiconductor substrate and then protrude out of the process chamber through the other side of the process chamber.

In another embodiment, the guide rod extends through the lower side of the process chamber and extends to the periphery of the semiconductor substrate. After extending, it may protrude out of the process chamber through the upper side of the process chamber.

The semiconductor manufacturing apparatus may further include a gas distribution plate installed inside the process chamber and distributing the reaction gas flowing into the gas inflow line in various directions in the chamber. In this case, the gas distribution plate may be installed on one side of the process chamber to which the gas inlet line is connected, but may be installed perpendicularly to the bottom surface of the process chamber. In this case, the guide rod may be fixed to the gas distribution plate.

In addition, the semiconductor manufacturing equipment is connected to the gas inlet line and the remote plasma generating unit for exciting the reaction gas flowing through the gas inlet line, and the reaction is installed in the process chamber and excited by the plasma generating unit It may further include a UV lamp for activating the gas.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided to ensure that the disclosed subject matter is thorough and complete, and that the scope of the invention to those skilled in the art will fully convey. Like numbers refer to like elements throughout.

Figure 2 is a schematic diagram showing an embodiment of a semiconductor manufacturing equipment according to the present invention, Figure 3 is a perspective view showing a gas distribution plate and the guide rods supported therein in FIG.

2 and 3, the semiconductor manufacturing apparatus 100 according to an embodiment of the present invention includes a process chamber 110 in which a process such as cleaning is performed, and a load lock chamber connected to the process chamber 110. 130). In this case, the process chamber 110 may be connected to a lower portion of the load lock chamber 130.

First, the load lock chamber 130 will be described. The load lock chamber 130 is a place where the semiconductor substrate 90 loaded from the outside temporarily waits for a predetermined time before being transferred to the process chamber 110. . Therefore, a gate valve 131 is installed at one side of the load lock chamber 130. Accordingly, the semiconductor substrate 90 loaded from the outside is transferred into the load lock chamber 130 through the gate valve 131. Thereafter, the gate valve 131 is closed while the process is in progress, and the inside of the load lock chamber 130 is changed to be equal to the internal pressure of the process chamber 110.

In addition, an opening 136 is formed below the load lock chamber 130, and the opening 136 is connected to the opening 123 of the process chamber 110. As a result, the semiconductor substrate 90 transferred into the load lock chamber 130 is transferred into the process chamber 110 through the connection part.

In addition, a space of a predetermined size is provided in the load lock chamber 130 so that a plurality of semiconductor substrates 90 are transferred at once, and a boat 150 transferred to the load lock chamber 130 at a lower portion of the space. Transfer unit 170 for transferring the to the process chamber 110 is provided. Therefore, the semiconductor substrate 90 may be loaded in a boat 150 or the like and transferred into the load lock chamber 130. In this case, the transfer unit 170 is moved in the vertical direction and the like, and transfers the semiconductor substrate 90 transferred to the load lock chamber 130 into the process chamber 110. Reference numeral 160 is a boat support for supporting the boat 150, reference numeral 133 is a gas introduction line for introducing an atmosphere gas into the load lock chamber 130, reference numeral 135 is to refer to the load lock chamber 130 Gas exhaust line for forming by vacuum.

The process chamber 110 includes an inner chamber 112 and an outer chamber 111 disposed outside the inner chamber 112. The inner chamber 112 is a place where the process such as cleaning proceeds directly. Therefore, a predetermined space is provided inside the inner chamber 112 so that the semiconductor substrate 90 loaded on the boat 150 is transferred into the inner chamber 112. In addition, a gas inflow line 115 through which a reaction gas for processing the semiconductor substrate 90 is introduced is provided at one side of the inner chamber 112, and the inner chamber 112 is located at the other side of the inner chamber 112. Exhaust line 116 is provided to exhaust the gas inside the reaction chamber and the reaction by-products generated inside the internal chamber 112. Therefore, the semiconductor substrate 90 transferred to the internal space of the inner chamber 112 is cleaned by the reaction gas introduced through the gas inflow line 115, and the reaction by-products generated during the cleaning process are exhaust lines. Exhaust through 116. Here, the gas inflow line 115 or the exhaust line 116 may be provided at the center of the side wall of the inner chamber 112, respectively.

In addition, a gas distribution plate 117 may be installed in the inner chamber 112 to distribute the reaction gas flowing into the gas inflow line 115 in various directions in the chamber 112. In one embodiment, the gas distribution plate 117 may be installed on one inner side of the inner chamber 112 to which the gas inlet line 115 is connected, but may be installed perpendicularly to the bottom surface of the inner chamber 112. have. In this case, the reaction gas introduced into the gas inflow line 115 may be distributed by the gas distribution plate 117 in the lower direction of the inner chamber 112 and the upper direction of the inner chamber 112.

On the other hand, the semiconductor manufacturing equipment 100 penetrates the heater 113 for heating the inner chamber 112, the outer chamber 111 and the inner chamber 112 to the inside of the inner chamber 112. Further comprising a guide rod 118 extending to the periphery of the semiconductor substrate 90 accommodated, and a thermocouple 119 inserted into the guide rod 118 to measure the temperature of the peripheral portion of the semiconductor substrate 90. Can be. In this case, the heater 113 may be used both a method using a halogen lamp and a method using a hot wire. In addition, the guide rod 118 may be formed in a hollow so that the thermocouple 119 is fitted therein, and may be formed of a material having high thermal conductivity, for example, aluminum. Therefore, the thermocouple 119 is fitted to the periphery of the semiconductor substrate 90 along the guide rod 118 to measure the temperature of the peripheral portion of the semiconductor substrate 90. Here, the guide rod 118 extends to the periphery of the semiconductor substrate 90 through the lower side of the outer chamber 111 and the inner chamber 112 and then inside the inner chamber 112. The predetermined length is extended to the upper portion of the inner chamber 112 along the stacked semiconductor substrate 90 by a height at which the 90 is stacked, and then the inner chamber 112 and the inner chamber 112 are disposed through the upper side of the inner chamber 112. It may protrude to the outside of the outer chamber 111. In this case, the guide rod 118 may be fixed to the gas distribution plate 117 installed perpendicular to the bottom surface of the inner chamber 112.

In addition, the semiconductor manufacturing equipment 100 is connected to the gas inlet line 115 and the remote plasma generating unit 190 to excite the reaction gas flowing through the gas inlet line 115, and the inner chamber 112 ) Is installed inside the UV lamp 114 for activating the reaction gas excited by the remote plasma generating unit 190 and the semiconductor substrate 90 transferred to the inner chamber 112 during the process. It may further include a substrate rotating unit 121 to rotate. Therefore, the reaction gas flowing into the inner chamber 112 proceeds with the cleaning process in a more activated state by the action of the remote plasma generating unit 190 and the UV lamp 114. Thus, the cleaning effect is further increased. In addition, since the semiconductor substrate 90 is rotated by the substrate rotating unit 121 while the semiconductor substrate 90 transferred to the inner chamber 112 is cleaned, the cleaning rate is entirely changed in the semiconductor substrate 90. It can be uniform. Reference numeral 180 is an inner valve for selectively communicating with the load lock chamber 130 and the process chamber 110, reference numeral 120 is a seat for the boat support 160 is seated, reference numeral 122 is a substrate rotating unit It is a rotating shaft connecting the 121 and the seating plate (120).

Hereinafter, a method of removing the natural oxide film using the semiconductor manufacturing apparatus 100 of the present invention as described above will be described in detail.

First, when the semiconductor substrates 90 on which the natural oxide film is formed are loaded into the semiconductor manufacturing apparatus 100 of the present invention with a large number of substrates loaded on the boat 150, the gate valve 131 of the load lock chamber 130 is opened. . Therefore, the semiconductor substrates 90 are transferred into the load lock chamber 130 through the gate valve 131 while being loaded in the boat 150.

Thereafter, when the semiconductor substrates 90 are transferred, the gate valve 131 is closed and the pressure of the load lock chamber 130 is changed and maintained at the same pressure as the pressure of the process chamber 110.

Subsequently, an inner valve 180 provided between the load lock chamber 130 and the process chamber 110 is opened, and the transfer unit 170 opens the semiconductor substrates 90 in the load lock chamber 130. Is transferred into the process chamber 110.

Thereafter, when the semiconductor substrates 90 are transferred into the process chamber 110, the inner valve 9170 is closed. At the same time, a reaction gas suitable for natural oxide film removal is supplied to the gas inlet line 115 connected to the process chamber 110, and the remote plasma generating unit 190 excites the supplied reaction gas. As a result, excited reaction gases are introduced into the process chamber 110 to remove the native oxide film formed on the semiconductor substrate 90. In addition, the heater 113 and the UV lamp 114 are driven together with or after the inflow of the reaction gas. Thus, the interior of the process chamber 110 is maintained at a temperature suitable for cleaning, during which the excited reactant gases are further activated by the action of light irradiated from the UV lamp 114. Here, NF ₃ gas containing a fluorine compound may be used as the reaction gas, and a mixed gas in which nitrogen and hydrogen are mixed may be used as a carrier gas for transporting it. In addition, the cleaning of the natural oxide layer may be performed for about 30 seconds. In this case, all of the natural oxide film formed on the semiconductor substrate 90 is cleaned (removed), and the reaction by-products generated during the cleaning are gradually removed from the semiconductor substrate 90 as the temperature inside the chamber 112 is increased. Separated and exhausted to the outside through the exhaust line 116.

On the other hand, the ambient temperature of the semiconductor substrate 90 which is directly cleaned in this natural oxide film cleaning process is very important. However, in the conventional case, since the ambient temperature of the inside of the chamber was measured only through the hole formed in the inner wall of one side of the chamber, the ambient temperature of the semiconductor substrate 90, which is directly cleaned, was measured. The temperature of the thermocouple and the temperature measured by the thermocouple had a lot of difference, which made it difficult to accurately control the process. However, in the present invention, the guide rod 118 extends through the outer chamber 111 and the inner chamber 112 and extends to the periphery of the semiconductor substrate 90 accommodated in the inner chamber 112. Since the thermocouple 119 is inserted into the guide rod 118 to measure the temperature of the peripheral portion of the semiconductor substrate 90, the ambient temperature of the semiconductor substrate 90 may be directly measured. Therefore, according to the present invention, it is possible to remove the natural oxide film formed on the semiconductor substrate 90 by accurate process management.

As mentioned above, although the present invention has been described with reference to the illustrated embodiments, it is only an example, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the scope of the present invention should be defined by the appended claims and their equivalents.

As described above, the semiconductor manufacturing equipment according to the present invention includes a guide rod extending through the inner chamber to the periphery of the semiconductor substrate accommodated in the inner chamber, and a thermocouple inserted into the guide rod to measure the temperature of the periphery of the semiconductor substrate. Since it is provided, it is possible to measure the ambient temperature of the semiconductor substrate which is directly cleaned. Therefore, according to the present invention, it is possible to remove the natural oxide film formed on the semiconductor substrate by precise process control of the cleaning process.

Claims (6)

A process chamber in which a semiconductor substrate is accommodated therein; A gas inlet line connected to the process chamber and into which a reaction gas for processing the semiconductor substrate is introduced; An exhaust line connected to the process chamber and configured to exhaust gas in the process chamber and reaction by-products generated in the process chamber; A heater for heating the interior of the process chamber; A guide rod extending through the process chamber to a periphery of the semiconductor substrate accommodated in the process chamber; And, And a thermocouple inserted into the guide rod to measure the temperature of the peripheral portion of the semiconductor substrate. The method of claim 1, The guide rod penetrates through one side of the process chamber and extends to the periphery of the semiconductor substrate, and then protrudes out of the process chamber through the other side of the process chamber. The method of claim 1, The guide rod penetrates through the lower side of the process chamber and extends to the periphery of the semiconductor substrate, and then extends along the semiconductor substrate to an upper portion of the process chamber by a height at which the semiconductor substrate is stacked in the process chamber. The semiconductor manufacturing equipment, characterized in that protruding out of the process chamber through the upper side of the chamber. The method of claim 1, And a gas distribution plate installed inside the process chamber and distributing the reaction gas flowing into the gas inlet line in various directions in the chamber. The method of claim 4, wherein The gas distribution plate is installed on one side of the inside of the process chamber connected to the gas inlet line, is installed perpendicular to the bottom surface of the process chamber, The guide rod is a semiconductor manufacturing equipment, characterized in that fixed to the gas distribution plate. The method of claim 1, A remote plasma generating unit connected to the gas inlet line and exciting the reaction gas introduced through the gas inlet line; And a UV lamp installed in the process chamber to activate a reaction gas excited by the plasma generating unit.

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