JP6422907B2 - Semiconductor manufacturing equipment - Google Patents

Description

  Embodiments described herein relate generally to a semiconductor manufacturing apparatus.

In a semiconductor manufacturing apparatus such as a CVD (Chemical Vapor Deposition) apparatus or an RIE (Reactive Ion Etching) apparatus, when a film forming process or an etching process is performed, a by-product accumulates in the exhaust pipe. By-products containing silicon can be removed using a cleaning gas such as, for example, ClF ₃ gas. Since heat is generated when such a by-product reacts with the cleaning gas, conventionally, the end point of cleaning has been detected by monitoring the temperature of the exhaust pipe.

  However, when the amount of by-products accumulated in the exhaust pipe gradually decreases due to cleaning, the amount of heat generated per unit area decreases. When the amount of heat generation decreases and the temperature of the exhaust pipe decreases, the reaction rate between the by-product and the cleaning gas decreases accordingly. For this reason, immediately before the end point of cleaning is detected, the cleaning process proceeds slowly over a long period of time at a relatively slow reaction rate. This increases the cleaning time.

JP 2006-004962 A

  Provided is a semiconductor manufacturing apparatus capable of shortening the cleaning time in an exhaust pipe.

The semiconductor manufacturing apparatus according to the present embodiment includes a first pipe that conveys exhaust gas from the reaction unit. The first supply unit supplies the cleaning gas to the first pipe. The heater is provided in the first pipe. The temperature sensor detects the temperature of the first pipe or the heater. The controller controls the power supplied to the heater based on the temperature detected by the temperature sensor. The controller controls the power supplied to the heater so that the temperature of the first pipe is substantially constant.

A block diagram showing an example of composition of semiconductor manufacturing device 1 by this embodiment. The graph which shows the relationship between the reaction heat from a reaction product, the supply heat from the heater 90, and the temperature of the exhaust piping 60. FIG. FIG. 5 is a flowchart showing an example of a cleaning process of the apparatus 1 according to the present embodiment.

  Embodiments according to the present invention will be described below with reference to the drawings. This embodiment does not limit the present invention.

  FIG. 1 is a block diagram showing an example of the configuration of the semiconductor manufacturing apparatus 1 (hereinafter also simply referred to as the apparatus 1) according to the present embodiment. The apparatus 1 may be, for example, a film forming apparatus such as a CVD apparatus or an epitaxial apparatus, or an etching apparatus such as an RIE apparatus.

  The apparatus 1 includes a chamber 10, a reaction gas supply unit 20, a processing controller 30, a pump 40, a detoxifying device 50, an exhaust pipe 60, a cleaning gas supply unit 70, a dilution gas supply unit 80, a heater. 90, a heater controller 95, and a temperature sensor S are provided.

  The chamber 10 as a reaction part can accommodate a semiconductor substrate (not shown), and forms a material film on the surface of the semiconductor substrate or etches the semiconductor substrate or the material film on the semiconductor substrate. Introduce reaction gas. The interior of the chamber 10 is regulated to a predetermined pressure by a pump 40 and a pressure adjustment valve (not shown), and receives the reaction gas from the reaction gas supply unit 20.

  The reactive gas supply unit 20 as the second supply unit is connected to the chamber 10 by piping and supplies the reactive gas to the chamber 10. The reaction gas may be, for example, a film forming gas containing silicon such as silane or silane chloride, or an etching gas containing fluorine such as sulfur fluoride or carbon fluoride.

  The process controller 30 controls each component of the apparatus 1 such as the chamber 10, the reaction gas supply unit 20, the pump 40, and the abatement apparatus 50, and executes a film forming process or an etching process. Further, the processing controller 30 controls the cleaning gas supply unit 70 and the dilution gas supply unit 80 to execute the cleaning process of the exhaust pipe 60.

  The pump 40 is connected to the chamber 10 via the exhaust pipe 60, and evacuates and depressurizes the inside of the chamber 10. The pump 40 evacuates the chamber 10 to guide the reaction product gas in the chamber 10 and the cleaning gas from the cleaning gas supply unit 70 to the exhaust pipe 60.

  The detoxifying device 50 is connected to the exhaust pipe 60, processes the reaction product gas and the cleaning gas to make them harmless, and discharges the processed gas to the outside of the device 1.

  The exhaust pipe 60 is connected from the chamber 10 to the pump 40 and the detoxifying device 50, and conveys the reaction product gas in the chamber 10 to the detoxifying device 50 through the pump 40. The exhaust pipe 60 is connected to a position different from the pipe of the reaction gas supply unit 20 and exhausts the reaction product gas generated during the film forming process or the etching process from the chamber 10. For the exhaust pipe 60, for example, a corrosion-resistant material such as stainless steel is used.

  When the reaction product gas passes through the exhaust pipe 60, the reaction product may liquefy or solidify and adhere to the inner wall of the exhaust pipe 60. For example, when the apparatus 1 performs a film forming process using silane or the like, a silane chloride polymer may adhere to the inner wall of the exhaust pipe 60 as a reaction product. When a large amount of reaction product accumulates in the exhaust pipe 60, the exhaust capacity and the decompression capacity of the pump 40 are adversely affected. Therefore, the apparatus 1 periodically cleans the inside of the exhaust pipe 60 using the cleaning gas from the cleaning gas supply unit 70.

The cleaning gas supply unit 70 as a first supply unit is connected to an exhaust pipe 60 in the vicinity of the chamber 10 and supplies the cleaning gas to the exhaust pipe 60. For example, ClF ₃ gas or NF ₃ gas is used as the cleaning gas. A cleaning gas such as ClF ₃ gas or NF ₃ gas can react with a reaction product such as chlorosilane polymer to remove the reaction product.

  The dilution gas supply unit 80 is connected to the exhaust pipe 60 near the chamber 10 together with the cleaning gas supply unit 70, and can supply the dilution gas together with the cleaning gas. As the dilution gas, for example, an inert gas such as nitrogen is used. The dilution gas is used to dilute the cleaning gas and control the reaction rate and heat of reaction between the cleaning gas and the reaction product.

  The heater 90 is provided around the exhaust pipe 60 and can heat the exhaust pipe 60. The heater 90 is provided with a temperature sensor S. The temperature sensor S detects the temperature of the exhaust pipe 60 or the heater 90 and outputs the detected temperature (temperature measurement value) to the heater controller 95. The heater 90 is preferably capable of heating the entire exhaust pipe 60, for example, a jacket heater capable of covering the entire periphery of the exhaust pipe 60 is desirable. Alternatively, the heater 90 may be provided in a part of the exhaust pipe 60. Further, as shown in FIG. 1, it is desirable that a plurality of temperature sensors S are provided in the heater 90 or the exhaust pipe 60.

  The heater controller 95 as a controller controls the electric power supplied to the heater 90 based on the temperature measurement value from the temperature sensor S. That is, the heater controller 95 feedback-controls the power supplied to the heater 90 using the temperature measurement value from the temperature sensor S. Thereby, the heater controller 95 can control the temperature of the heater 90 and the exhaust pipe 60. For example, the heater controller 95 controls the power supplied to the heater 90 so that the temperatures of the heater 90 and the exhaust pipe 60 are substantially constant. Thereby, the reaction rate between the cleaning gas and the reaction product can be stabilized. Further, the heater / controller 95 outputs a control signal CNT to the processing controller 30 based on the temperature measurement value of the temperature sensor S and the rate of change of the temperature measurement value. The processing controller 30 controls the cleaning gas supply unit 70 and / or the dilution gas supply unit 80 according to the control signal CNT. Thus, the processing controller 30 can adjust the flow rate of the cleaning gas or the flow rate of the dilution gas according to the temperature of the exhaust pipe 60.

  FIG. 2 is a schematic graph showing the relationship between the reaction heat from the reaction product, the supply heat from the heater 90, and the temperature of the exhaust pipe 60. The vertical axis represents the reaction heat (kcal) from the reaction product, the supply heat (kcal) from the heater 90 and the temperature (° C.) of the exhaust pipe 60. The horizontal axis represents the elapsed time from the start of the cleaning process. Incidentally, t0 is the cleaning process start time.

  Line L1 indicates the reaction heat from the reaction product (that is, the reaction heat between the cleaning gas and the reaction product). Line L <b> 2 indicates heat supplied from the heater 90. The supply heat from the heater 90 is heat generated from the heater 90 that receives power supply from the heater controller 95. A line L3 indicates the temperature of the exhaust pipe 60 or the heater 90 (that is, the temperature measurement value detected by the temperature sensor S).

  When the cleaning gas reacts with the reaction product, reaction heat is generated. When a large amount of reaction product adheres to the inner wall of the exhaust pipe 60 at the beginning of the cleaning process, as shown by the line L1, the reaction heat from the reaction product rapidly increases in a short time (t0 to t0). t1). As the cleaning process proceeds and the amount of reaction product decreases, the reaction heat from the reaction product decreases (t1 to t2).

  Here, in the present embodiment, as indicated by the line L2, the heater controller 95 controls the power supply to the heater 90 so that the temperature of the exhaust pipe 60 or the heater 90 is substantially constant. Thereby, the sum of the reaction heat from the reaction product and the supply heat from the heater 90 can be maintained substantially constant. That is, the heat supplied from the heater 90 is the reaction product so that the total amount of heat in the reaction product and the heater 90 is substantially constant (so that the heat supplied from the heater 90 supplements the heat of reaction from the reaction product). Changes inversely with the increase or decrease in reaction heat from the object. For example, the supply heat from the heater 90 decreases when the reaction heat from the reaction product increases, and increases when the reaction heat from the reaction product decreases. By making the temperature of the exhaust pipe 60 or the heater 90 substantially constant, the reaction rate between the cleaning gas and the reaction product can be stabilized.

  If the heater 90 is not provided, the temperature of the exhaust pipe 60 changes with the reaction heat from the reaction product. Therefore, the temperature of the exhaust pipe 60 becomes maximum immediately after t1 or t1, and then decreases toward t2. In this case, the reaction rate between the cleaning gas and the reaction product also changes with the temperature of the exhaust pipe 60. Therefore, before and after t1, the reaction rate between the cleaning gas and the reaction product is fast, but thereafter the reaction rate gradually decreases. As a result, when the reaction product is decomposed and reduced to some extent, the reaction between the cleaning gas and the reaction product becomes slow, and the time until the cleaning process is completed becomes long. In FIG. 2, the tail (tail) in the vicinity of t2 of the line L1 becomes long.

  On the other hand, in the apparatus 1 according to this embodiment, the supply heat from the heater 90 supplements the reaction heat from the reaction product, and the temperature of the exhaust pipe 60 or the heater 90 is made substantially constant. Accordingly, the reaction rate between the cleaning gas and the reaction product is stabilized, and the reaction product can be decomposed and removed at a substantially constant rate. As a result, the reaction rate between the cleaning gas and the reaction product is maintained even if the reaction product is decomposed and reduced to some extent, and the time until the end of the cleaning process is shortened. That is, the tail (tail) in the vicinity of t2 of the line L1 is shortened.

Further, if the heater 90 heats the exhaust pipe 60 with a constant output, the temperature of the exhaust pipe 60 still varies with the reaction heat from the reaction product. In this case, since the heat supplied from the heater 90 is further added, the temperature of the exhaust pipe 60 may become very high immediately after t1 or t1. If the temperature is too high, the cleaning gas may be decomposed and deactivated. For example, ClF ₃ gas is decomposed at a temperature of about 180 ° C. That is, the critical temperature of ClF ₃ gas is about 180 ° C. Therefore, when the temperature of the exhaust pipe 60 exceeds about 180 ° C. due to the reaction heat from the reaction product and the heat supplied from the heater 90, there is a possibility that the cleaning process cannot be performed. Further, if the temperature is too high, the exhaust pipe 60 (for example, stainless steel) and the flange surface sealing material (O-ring) (not shown) may be corroded or deteriorated by reaction products. On the other hand, if the supply heat from the heater 90 is too low, as described above, when the reaction product is decomposed to some extent and decreases, the time until the end of the cleaning process becomes long.

  On the other hand, in the apparatus 1 according to the present embodiment, the supply heat from the heater 90 is changed according to the reaction heat from the reaction product so that the total amount of heat in the reaction product and the heater 90 is substantially constant. Thereby, the temperature of the exhaust pipe 60 or the heater 90 can be controlled to be substantially constant. For example, the temperature of the exhaust pipe 60 or the heater 90 is controlled to a temperature of about 100 ° C. in consideration of the critical temperature of the cleaning gas and the corrosion of the exhaust pipe 60. Thereby, the apparatus 1 can shorten the cleaning time without suppressing the cleaning process while suppressing the corrosion of the exhaust pipe 60.

For example, the reaction rate between a cleaning gas (eg, CLF ₃ gas) and a reaction product (eg, silane chloride) is about 10 at 100 ° C. compared to 25 ° C. calculated from their activation energy. It is estimated that it will be doubled. Therefore, when the reaction product is reduced, the heater 90 heats the exhaust pipe 60, whereby the reaction between the cleaning gas and the reaction product is promoted, and the cleaning process can be completed in a short time.

  The end point of the cleaning process may be determined by the rate of change per unit time of the power supplied to the heater 90. For example, as indicated by the line L2, the rate of change in the power supplied to the heater 90 is large when the reaction between the reaction product and the cleaning gas is in progress (0 to t2). However, when the amount of reaction products decreases and the cleaning process approaches the end point, the rate of change in the power supplied to the heater 90 decreases (t2). For example, in the vicinity of t1, the slope of the tangent line L2 is relatively large. However, after t2, the slope of the tangent line L2 becomes relatively small. Therefore, the heater controller 95 and the processing controller 30 may stop supplying the cleaning gas when the rate of change of the power supplied to the heater 90 per unit time becomes less than a certain threshold value. As a result, the cleaning process can be automatically terminated when the amount of the reaction product is almost exhausted.

  Note that the end point of the cleaning process may be determined based on the time from the start of the cleaning process. In this case, the process controller 30 ends the cleaning process after a predetermined time has elapsed from the start of the cleaning process based on the statistically obtained cleaning time. Even in this case, the cleaning process can be automatically terminated. Of course, the end point of the cleaning process may be determined using both the rate of change in the power supplied to the heater 90 and the elapsed time from the start of the cleaning process.

  Next, the operation of the device 1 according to the present embodiment will be described.

  FIG. 3 is a flowchart showing an example of the cleaning process of the apparatus 1 according to the present embodiment. The process controller 30 performs a film forming process or an etching process using the chamber 10 and the reactive gas supply unit 20. At this time, the pump 40 exhausts the inside of the chamber 10 through the exhaust pipe 60 in order to exhaust the reaction product gas generated in the film forming process or the etching process from the chamber 10. After repeatedly performing the film forming process or the etching process, the process controller 30 starts the cleaning process.

  First, the heater controller 95 supplies power to the heater 90 and heats the exhaust pipe 60 to a predetermined temperature (S10). At this time, the reaction between the cleaning gas and the reaction product has not yet started. Accordingly, the exhaust pipe 60 is heated to a predetermined temperature by the heat supplied from the heater 90.

  Next, the cleaning gas supply unit 70 supplies the cleaning gas to the exhaust pipe 60 (S20). Thereby, the reaction product adhering to the inner wall of the exhaust pipe 60 reacts with the cleaning gas. Accordingly, reaction heat is generated from the reaction product. At this time, the supply amount of the dilution gas may be arbitrary.

  While the reaction between the cleaning gas and the reaction product proceeds, the heater controller 95 receives feedback of the temperature measurement value from the temperature sensor S so that the temperature of the heater 90 and the exhaust pipe 60 becomes substantially constant. The power supplied to the heater 90 is controlled (S30).

  At this time, the heater controller 95 and the processing controller 30 may control the content rate of the dilution gas included in the cleaning gas so that the temperatures of the heater 90 and the exhaust pipe 60 become substantially constant. In this case, it takes some time until the temperature of the heater 90 and the exhaust pipe 60 is reflected after adjusting the supply amount of the cleaning gas and / or the supply amount of the dilution gas. However, even with such a method, it is possible to control the temperature of the heater 90 and the exhaust pipe 60.

  Here, when the reaction heat from the reaction product is very large, the temperature of the heater 90 and the exhaust pipe 60 may become too high even if the heater controller 95 stops supplying power to the heater 90. In order to cope with such a situation, the device 1 may have an interlock function.

  For example, when the temperature of the heater 90 and the exhaust pipe 60 becomes equal to or higher than the threshold temperature (first temperature) (YES in S35), the heater controller 95 raises the control signal CNT and transmits it to the processing controller 30 (S40). ). The process controller 30 controls the cleaning gas supply unit 70 in response to the control signal CNT to reduce the supply amount of the cleaning gas or stop the supply thereof. In addition, or alternatively, the process controller 30 controls the dilution gas supply unit 80 in accordance with the control signal CNT to increase the supply amount (content rate) of the dilution gas (S50). By reducing the supply amount of the cleaning gas or stopping the supply thereof, the reaction between the cleaning gas and the reaction product is suppressed, so that the reaction heat from the reaction product is suppressed. As a result, the temperature of the heater 90 and the exhaust pipe 60 decreases. Further, even if the supply amount of the dilution gas (content ratio with respect to the cleaning gas) is increased, the temperature of the heater 90 and the exhaust pipe 60 is similarly lowered. Such an interlock function may be performed by adjusting one or both of the supply amount of the cleaning gas and the supply amount of the dilution gas.

  When the temperature of the heater 90 and the exhaust pipe 60 becomes lower than the threshold temperature by the operation of step S50 (YES in S55), the heater controller 95 lowers the control signal CNT and supplies the cleaning gas supply unit 70 and the dilution gas. The unit 80 is restored (S60). Thereby, the supply amount of the cleaning gas and the supply amount of the dilution gas are returned to those supply amounts in steps S20 and S30. Then, the process returns to step S20 to continue the cleaning process.

  When the temperature of the heater 90 and the exhaust pipe 60 is lower than the threshold temperature (first temperature) (NO in S35), the heater controller 95 and the processing controller 30 have a rate of change per unit time of the power supplied to the heater 90. It is determined whether it is less than the threshold value (S70). Here, the heater controller 95 monitors not only the temperature of the exhaust pipe 60 or the heater 90 but also the rate of change per unit time of the power supplied to the heater 90. When the rate of change per unit time of the power supplied to the heater 90 is equal to or greater than the threshold (NO in S70), the heater controller 95 and the processing controller 30 determine that most of the reaction products have not yet been removed, The cleaning process is continued without changing the supply amount of the cleaning gas and the supply amount of the dilution gas (S20).

  On the other hand, when the rate of change per unit time of the power supplied to the heater 90 is less than the threshold (YES in S70), the heater controller 95 and the processing controller 30 indicate that the reaction product in the exhaust pipe 60 has been removed. Judgment is made and the supply of the cleaning gas is stopped (S80).

  As described above, in the apparatus 1 according to the present embodiment, the supply heat from the heater 90 supplements the reaction heat from the reaction product, and the temperature of the exhaust pipe 60 or the heater 90 is made substantially constant. As a result, even when the amount of reaction products decreases, the reaction rate between the cleaning gas and the reaction products is maintained, and the time until the end of the cleaning process is shortened.

  Further, the heater controller 95 reduces the supply amount of the cleaning gas or stops the supply thereof when the temperature of the exhaust pipe 60 or the heater 90 becomes equal to or higher than the threshold temperature. In addition or alternatively, the heater controller 95 increases the content of the inert gas contained in the cleaning gas when the temperature of the exhaust pipe 60 or the heater 90 becomes equal to or higher than the threshold temperature. By providing such an interlock function, the apparatus 1 maintains the temperature of the exhaust pipe 60 or the heater 90 below the threshold temperature, suppresses corrosion of the exhaust pipe 60, and decomposes and deactivates the cleaning gas. Can be suppressed. As a result, the cleaning time can be shortened without stagnation of the cleaning process.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 ... Apparatus, 10 ... Chamber, 20 ... Reaction gas supply part, 30 ... Processing controller, 40 ... Pump, 50 ... Detoxification device, 60 ... Exhaust piping, 70 ... Cleaning gas supply unit, 80 ... Dilution gas supply unit, 90 ... Heater, 95 ... Heater controller, S ... Temperature sensor

Claims (7)

A first pipe for conveying exhaust gas from the reaction section;
A first supply unit for supplying a cleaning gas to the first pipe;
A heater provided in the first pipe;
A temperature sensor for detecting the temperature of the first pipe or the heater;
A controller for controlling the power supplied to the heater based on the temperature detected by the temperature sensor;
The said controller is a semiconductor manufacturing apparatus which controls the electric power supplied to the said heater so that the temperature of the said 1st piping may be made substantially constant . A first pipe for conveying exhaust gas from the reaction section;
A first supply unit for supplying a cleaning gas to the first pipe;
A heater provided in the first pipe;
A temperature sensor for detecting the temperature of the first pipe or the heater;
A controller for controlling the power supplied to the heater based on the temperature detected by the temperature sensor;
The said controller is a semiconductor manufacturing apparatus which controls the content rate of the inert gas contained in the said cleaning gas so that the temperature of the said 1st piping or the said heater may be made substantially constant. A first pipe for conveying exhaust gas from the reaction section;
A first supply unit for supplying a cleaning gas to the first pipe;
A heater provided in the first pipe;
A temperature sensor for detecting the temperature of the first pipe or the heater;
A controller for controlling the power supplied to the heater based on the temperature detected by the temperature sensor;
The controller is a semiconductor manufacturing apparatus that reduces the supply amount of the cleaning gas or stops the supply of the cleaning gas when the temperature of the first pipe or the heater is equal to or higher than the first temperature. A first pipe for conveying exhaust gas from the reaction section;
A first supply unit for supplying a cleaning gas to the first pipe;
A heater provided in the first pipe;
A temperature sensor for detecting the temperature of the first pipe or the heater;
A controller for controlling the power supplied to the heater based on the temperature detected by the temperature sensor;
The said controller is a semiconductor manufacturing apparatus which increases the content rate of the inert gas contained in the said cleaning gas, when the temperature of the said 1st piping or the said heater becomes more than 1st temperature. Wherein the controller controls the content of the inert gas contained in the cleaning gas to a substantially constant temperature of the first pipe or the heater, according to any one of claims 1 to 4 Semiconductor manufacturing equipment. 6. The controller according to claim 1, wherein when the temperature of the first pipe or the heater becomes equal to or higher than the first temperature, the controller decreases the supply amount of the cleaning gas or stops the supply thereof . The semiconductor manufacturing apparatus according to one item . 7. The controller according to claim 1, wherein the controller increases the content rate of the inert gas contained in the cleaning gas when a temperature of the first pipe or the heater becomes equal to or higher than a first temperature . The semiconductor manufacturing apparatus according to one item .

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