KR20050073154A - Apparatus for manufacturing a substrate - Google Patents

Abstract

Lifters are disposed at equal intervals between the chamber inner wall and the chuck, and a shadow ring is disposed in the horizontal direction at the upper end of the lifter. A chuck is positioned below the shadow ring, and a semiconductor substrate is seated above the chuck. A sensor is built in the lower portion of the shadow ring facing the semiconductor substrate to measure the distance between the semiconductor substrate and the shadow ring. The process member operates the lifter in accordance with the distance measured from the sensor to adjust the distance between the shadow ring and the semiconductor substrate. The gap between the semiconductor substrate and the shadow ring, which is preferable for each unit process, is set in the process member so that the gap between the semiconductor substrate and the shadow ring is optimally formed. By attaching a sensor to the shadow ring to accurately measure the gap between the semiconductor substrate and the shadow ring, and controlling the lifter according to the measurement result, the gap between the semiconductor substrate and the shadow ring can be optimally formed. Therefore, process efficiency can be increased and the error rate of a subsequent process can be reduced.

Description

Semiconductor Substrate Processing Equipment {APPARATUS FOR MANUFACTURING A SUBSTRATE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor substrate processing apparatus, and more particularly, to a dry etching apparatus including a shadow ring for preventing the edge of a wafer from being damaged by plasma gas.

Current research on semiconductor devices is progressing toward high integration and high performance in order to process more data in a short time. In order to achieve high integration and high performance of a semiconductor device, a technique of accurately etching a thin film pattern on a wafer is important.

In order to produce a semiconductor device, a circuit pattern is exposed on a wafer on which a predetermined thin film is formed, and then the circuit pattern is formed through an etching process. In this case, a precise etching process is required as well as the exposure process.

In the etching process, the semiconductor product having the desired performance could be produced by the wet etching method in the semiconductor product with low integration and processing speed, but the wet etching with low precision of thin film formation was increased as the processing speed and integration degree increased. Instead, high precision dry etching is used.

Dry etching generates a highly reactive plasma gas by exposing the reaction gas to an electric field to allow the outermost electrons to escape, and using the plasma gas, the wafer or the thin film already formed on the wafer is etched to fit the circuit pattern.

More specifically about plasma, plasma melts when heated to a solid material at low temperature, turns into a weak substance, evaporates and turns into a gas, and when further heat is applied, each atom breaks into electrons and cations, causing the fourth state of the material. Becomes The fourth state is a plasma state.

Plasma is composed of electrons, ions, and neutral particles, which are free charged particles, and is electrically neutral.

Since the integration of semiconductors has increased rapidly in the mid-1980s, a technique for miniaturizing line widths at high aspect ratios is urgently needed. Conventional wet etching techniques cannot satisfy the above process conditions due to isotropic etching characteristics, and thus, plasma technologies capable of anisotropic etching have been developed.

Plasma etching can be largely divided into sputtering etching, chemical etching, etching with the help of ions, and etching with ion bombardment and side protective film.

Sputtering etching is performed by bombarding the thin film with high energy ions accelerated by the plasma sheath. When the energy of ions is greater than the surface atom binding energy, the surface atoms are released from the surface and etching proceeds. This reaction is a purely physical reaction, so the gas pressure must be low to prevent back scattering.

Chemical etching causes radicals generated in the plasma to reach the surface of the thin film to induce chemical reaction with the film. Chemical reactions produce volatile reaction products and produce many reaction products in order to continue etching. Low volatility leaves the reaction product on the surface, preventing the chemical reaction of radicals with the substrate material. In this case, the plasma can be etched isotropically without the direction of etching by supplying radicals, and the selectivity is high.

Etching by ion assist uses neutral radicals that cause chemical reactions with the membrane in the presence of ion bombardment. In this case, the neutral radicals collide with the ions to increase the etching synergy. Even in etching with the aid of ions, the etching rate is changed depending on the type of reaction gas, the flow rate of radicals reaching the surface state of the thin film, and the like.

When the thin etching is performed by performing the dry etching as described above, the plasma gas may be contacted and all the etchable materials are etched. Therefore, it is necessary to block the area that is not necessarily etched to be exposed to the plasma.

In fact, the peripheral portion of the wafer where the thin film pattern is not formed together with the portion where the thin film pattern is formed is etched, or the end of the film quality adjacent to the peripheral portion of the wafer is etched, causing many defects. When the periphery of the wafer is etched, particles are generated which can cause process errors in subsequent processing. In addition, when the end of the film quality adjacent to the peripheral portion of the wafer is etched, the entire film quality may be lifted, which may cause a problem of deteriorating its own characteristics.

In order to solve the above problems, there is disclosed a technique for preventing the peripheral portion of the wafer from being exposed to the plasma gas by using the shadow ring during the etching process. However, in the related art, the shadow ring is fixed inside the process chamber, and thus it is difficult to control the distance between the shadow ring and the wafer during the etching process.

To get the most out of the shadow ring, keep the shadow ring as close to the wafer as possible. However, the thickness of the film formed on the wafer is changed each time a predetermined unit process is performed, and the gap between the shadow ring and the wafer is changed because the film may or may not remain on the periphery of the wafer. If the distance between the shadow ring and the wafer is not adjusted in response to the change, the effect of using the shadow ring is reduced.

Conventionally, the etching process is performed after setting the etching apparatus by roughly predicting the distance between the shadow ring and the wafer. If the etching result of the wafer in which the etching process is performed in the etching apparatus is poor, a try and error method of setting the etching apparatus in anticipation of the distance between the shadow ring and the wafer is used again. However, the try and error method incurs enormous losses both in time and in economics. Furthermore, in order to adjust the distance between the shadow ring and the wafer, the semiconductor substrate processing apparatus needs to be disassembled to manually change the mounting position of the shadow ring. The shadow ring may be incorrectly mounted according to the skill of the operator.

As described above, if the gap between the shadow ring and the wafer cannot be accurately maintained during the etching process, the precision of the process may be degraded, and the error of the subsequent process and the characteristics of the semiconductor device may be degraded.

The present invention has been made to solve the above-described problems of the prior art, an object of the present invention is to attach a proximity sensor to the shadow ring to measure the distance between the shadow ring and the semiconductor substrate, the shadow according to the distance measured from the sensor The present invention provides a semiconductor substrate processing apparatus capable of precisely adjusting a gap between a shadow ring and a semiconductor substrate by controlling a lifter provided with a ring.

In order to achieve the object of the present invention described above, a semiconductor processing apparatus according to a preferred embodiment of the present invention is installed in the upper end of the lifter, the lifter is extended and contracted in the vertical direction between the process chamber, the chuck, the chuck and the inner wall of the process chamber. A shadow ring, a sensor installed at an end of the shadow ring to measure a distance between the shadow ring and the semiconductor substrate, and a process member receiving information from the sensor to control the stretching and contraction of the lifter. In this case, the sensor is a non-contact sensor using light.

According to the present invention, it is possible to accurately adjust the distance between the shadow ring and the semiconductor substrate by installing a sensor at the end of the shadow ring to measure the gap with the semiconductor substrate, and control the lifter to support and lift the shadow ring according to the measured interval. have. Therefore, particle generation and deterioration of semiconductor characteristics are prevented, and process efficiency and semiconductor characteristics are improved.

Hereinafter, a semiconductor substrate processing apparatus according to exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, but the present invention is not limited or limited to the following embodiments.

1 is a schematic cross-sectional view for describing a semiconductor substrate processing apparatus according to an exemplary embodiment of the present invention, FIG. 2 is an enlarged cross-sectional view for explaining the sensor shown in FIG. 1, and FIG. 3 is shown in FIG. 1. It is a schematic sectional drawing for demonstrating the semiconductor substrate processing apparatus which concerns on another embodiment which modified the lifter.

1 and 2, the semiconductor substrate processing apparatus includes a process chamber 100, a lifter 110, a shadow ring 120, a sensor 130, a chuck 140, a heater member 150, and a gas supply member. 160, and a power supply member 170.

The process chamber 100 includes a space enclosed from the outside. In the process chamber 100, a predetermined process for the semiconductor substrate W is performed. A process of depositing a predetermined film on the semiconductor substrate W, a process of etching the deposited film, or the like may be performed in the process chamber 100. Meanwhile, an exhaust port 101 for discharging the reaction by-products and the unreacted gas generated during the progress of the film forming process is formed below the process chamber 100.

In the center of the process chamber 100, a chuck 140 for supporting the semiconductor substrate W is installed. An electrostatic generating member or a vacuum member may be added or installed in the chuck 140 to selectively fix the semiconductor substrate W.

The heater member 150 is installed inside the chuck 140. The heater member 150 heats the semiconductor substrate W disposed thereon. The heater member 150 includes a first heater 151 and a second heater 152. The first heater 151 is disposed adjacent to the center of the chuck 140, and the second heater 152 is disposed adjacent to the peripheral portion of the chuck 140. The semiconductor substrate W is heated by radiant heat generated and transmitted by the first heater 151 and the second heater 152.

The gas supply member 160 is installed in the process chamber 100 above the chuck 140. The gas supply member 160 has a shape such as a shower head. The gas supply member 160 supplies a reaction gas for processing the semiconductor substrate W into the process chamber 100.

The gas supply member 160 is connected to a power supply member 170 for providing high frequency power to the process chamber 100. The power supply member 170 forms an electric field in the process chamber 100 to change the reaction gas into a plasma state.

In order to change the reaction gas into a plasma state more actively, an electric field of a high potential difference must be formed in the process chamber 100. As a method for forming an electric field of a high potential difference, there is a method of grounding the chuck 140. When the chuck 140 is grounded, the chuck 140 becomes a cathode and the gas supply member 160 becomes an anode.

The reaction gas changed into a plasma state (hereinafter referred to as plasma gas) processes the semiconductor substrate W seated on the chuck 140. An example of a process in which the plasma gas processes the semiconductor substrate W includes an etching process and a deposition process. Techniques for using plasma gases in etching and deposition processes are disclosed in many publications, and descriptions thereof are omitted in this embodiment.

In the semiconductor substrate processing process using the plasma gas, the shadow ring 120 is used to prevent the peripheral portion of the semiconductor substrate W from being exposed to the plasma gas.

The shadow ring 120 has a ring shape as a whole. The outer diameter of the shadow ring 120 is larger than the diameter of the semiconductor substrate W, and the inner diameter of the shadow ring 120 is smaller than the diameter of the semiconductor substrate W. The shadow ring 120 is preferably made of a material having excellent thermal stability such as graphite or ceramic. The shadow ring 120 is supported by the lifter 110 to move up and down. Hereinafter, the shadow ring 120, the lifter 110, and the sensor 130 will be described in detail.

At least two or more lifters 110 are disposed at equal intervals between the inner wall of the process chamber 100 and the chuck 140. That is, the lifter 110 is disposed along the periphery of the chuck 140. The lifter 110 is extended or contracted in the vertical direction inside the chamber 100. In this case, each lifter 140 is connected to the process member 180 to control the lift. In this embodiment, only the lifter 110 provided between the inner wall of the process chamber 100 and the chuck 140 will be described. However, the lifter 110 may be installed on the upper portion of the chamber 100. The important thing is that the distance between the shadow ring 120 and the semiconductor substrate W is adjusted by the lifter 110.

The shadow ring 120 is disposed in the horizontal direction and fixed to the upper end of the lifters 110. The shadow ring 120 is supported by the lifters 110 and is lifted as the lifter 140 is extended or contracted. The shadow ring 120 supported by the lifter 110 is located above the chuck 140. Since the shadow ring 120 has a shape similar to that of the semiconductor substrate W, the shadow ring 120 disposed on the lifter 110 is adjacent to the peripheral portion of the semiconductor substrate W. As shown in FIG.

FIG. 2 is an enlarged cross-sectional view for explaining the sensor illustrated in FIG. 1. Referring to FIG. 2, a sensor 130 is installed at a lower portion of the shadow ring 120 facing the semiconductor substrate W. Referring to FIG. More precisely, sensor 130 is partially embedded in shadow ring 120.

In general, since the thickness of the shadow ring 120 is about 10 to 20 mm, it may be difficult to embed the sensor 130 in the shadow ring 120. However, thanks to the development of semiconductor devices, many miniature sensors have been developed, and the sensor 130 may be integrally manufactured by the built-in method of the shadow ring 120 or may be manufactured by attaching to the outside of the shadow ring 120. As will be appreciated, there will be no great difficulty in the implementation by those skilled in the art.

The sensor 130 used in this embodiment is a non-contact proximity sensor using light. The sensor 130 irradiates the light downward and collects the reflected light generated by the light reflected on the semiconductor substrate W to measure the distance between the sensor 130 and the semiconductor substrate W. In this embodiment, a displacement measuring micro sensor using a laser is used, but a fiber sensor, a sensor using a magnetic field, or a sensor using ultrasonic waves can also be used.

The sensor 130 irradiates light to the periphery of the semiconductor substrate W seated on the chuck 140 to determine a distance t (hereinafter, referred to as a measurement interval) between the shadow ring 120 and the semiconductor substrate W. FIG. Measure The interval t measured from the sensor 130 is provided to the process member 180.

The process member 180 compares the interval between the predetermined shadow ring 120 and the semiconductor substrate W (hereinafter, referred to as a target interval) and the measured interval t. If the target interval is smaller or larger than the measurement interval t, the lifter 110 is stretched or contracted to pause the target interval and the measurement interval t.

In order to maximize the effect of the shadow ring 120, the distance between the shadow ring 120 and the semiconductor substrate W should be kept as narrow as possible. In the job profile, an optimum distance, ie, a target distance, between the shadow ring 120 and the semiconductor substrate W is defined for each unit process, which is stored in the process member 180.

Process conditions and sequences performed in the process chamber 100 are defined in recipes, and the recipes are input to the semiconductor substrate processing apparatus through the process member 180. In this case, each target interval may be included in a recipe to reduce the trouble of having to reset the target interval every time the other semiconductor substrate W is provided to the process chamber 100. In addition, the gap between the shadow ring and the wafer may be roughly anticipated, thus reducing process errors occurring during the etching process.

It is preferable to lift the lifter 110 while keeping the shadow ring 120 horizontal. However, in further development, it may not be desirable to raise and lower the shadow ring 120 horizontally. As an example, the semiconductor substrate W is not disposed horizontally on the chuck 140. In this case, the shadow ring 120 may be disposed to be slightly inclined to optimally maintain the distance from the semiconductor substrate W. FIG. The lifters 110 according to the present exemplary embodiment may be independently lifted, so that the shadow ring 120 may be slightly inclined on the semiconductor substrate W. FIG. This may be implemented by the process member 180 controlling the respective lifters 110 according to the distance between the shadow ring 120 and the semiconductor substrate W measured by the sensor 130. In the semiconductor substrate processing apparatus according to the present exemplary embodiment, the lifter 110 may be independently removed, and thus the gap between the shadow ring 120 and the semiconductor substrate W may be optimally maintained. Therefore, the gap between the shadow ring and the wafer can be roughly anticipated, so that process errors occurring during the etching process can be further reduced.

Lifter 110 for adjusting the height of the shadow ring 120 may be implemented in various ways. Hereinafter, a semiconductor substrate processing apparatus according to another exemplary embodiment in which the lifter is modified will be described in detail with reference to FIG. 3. In this case, description of the semiconductor substrate processing apparatus overlapping with the above description is omitted.

Referring to FIG. 3, at least two lifter shafts 211 are disposed between the inner wall of the process chamber 200 and the chuck 240. The lifter shafts 211 are arranged at equal intervals along the periphery of the chuck 240. All the lifter shafts 211 are connected to the lifter driver 210 which moves up and down through the bottom center of the process chamber 200. The lifter shafts 211 are supported by the lifter driver 210 and are elevated to the same height.

The shadow ring 220 is fixed to the end of the lifter shaft 211 as described above. As the lifter driver 210 moves up and down, the lifter shaft 211 also moves up and down, and as the lifter shaft 211 moves up and down, the shadow ring 220 also moves up and down.

Since the shadow ring 220 must be raised and leveled in the process chamber 200, all lifter shafts 211 are preferably elevated to the same height. Therefore, there is no need to lift and lift the ball lifter shaft 211 individually. After installing the lifter driver 210 so that the lifter shafts 211 have the same height as in the present embodiment, when only the lifter driver 210 is lifted, all the lifter shafts 211 can be lifted to the same height. . Further, the structure of the semiconductor substrate processing apparatus can be simplified and the convenience of control can be obtained. However, as described above, the height of the lifter shaft 211 cannot be individually controlled, which is a matter that those skilled in the art can sufficiently select and deform.

The installation position of the sensor 230 with respect to the shadow ring 220 and the interlocking principle of the process member 280 and the sensor 230 are almost the same as described above, and thus redundant description thereof will be omitted.

According to the present invention, by installing a sensor in the shadow ring, and by controlling the lifter for adjusting the height of the shadow ring in accordance with the distance between the shadow ring and the semiconductor substrate measured from the sensor, the distance between the shadow ring and the semiconductor substrate is optimized Can be adjusted. Therefore, the efficiency of the semiconductor substrate processing process such as the etching process can be improved, and the process error rate can be greatly reduced.

As described above, the present invention has been described with reference to the preferred embodiments, but those skilled in the art can variously modify the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. It will be appreciated that it can be changed.

1 is a schematic cross-sectional view for describing a semiconductor substrate processing apparatus according to a preferred embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view for explaining the sensor illustrated in FIG. 1.

3 is a schematic cross-sectional view for describing a semiconductor substrate processing apparatus according to another exemplary embodiment in which the lifter illustrated in FIG. 1 is modified.

<Explanation of symbols for the main parts of the drawings>

100, 200: Chamber 101: Exhaust vent

110: Lifter 120, 220: Shadow ring

130, 230: sensor 140, 240: chuck

150: heater member 151: first heater

152: Second heater 160: Gas supply member

170: power supply member 180, 280: process member

211 ： lifter shaft 210 ： lifter driver

W: semiconductor substrate

Claims (5)

A process chamber for performing a predetermined process on the semiconductor substrate; A chuck disposed within the process chamber to support the semiconductor substrate; A shadow ring disposed in the chamber in a horizontal direction so as to be adjacent to a periphery of the semiconductor substrate supported on the chuck; A lifter for supporting the shadow ring and for moving the shadow ring in a vertical direction; A sensor installed at an end of the shadow ring to measure a distance between the shadow ring and the semiconductor substrate; And And a process member for receiving the information on the gap from the sensor to control the lifting of the lifter. The lifter of claim 1, wherein the lifter comprises: at least two lifter shafts disposed at equal intervals along the circumference of the chuck and supporting the shadow ring; And And a driver connected to the lifter shafts to lift and lift the lifter shaft in a vertical direction. The semiconductor substrate processing apparatus of claim 1, wherein the sensor is embedded at a lower portion of the shadow ring facing the semiconductor substrate supported by the chuck. The semiconductor substrate processing apparatus of claim 1, wherein the sensor is a non-contact sensor using light. The gas supply apparatus of claim 1, further comprising: a gas supply member communicating with an inside of the process chamber to supply a reaction gas into the chamber; And And a power supply member for forming an electric field inside the process chamber to convert the reaction gas into a plasma state.