JP2006186015A - Substrate processing equipment - Google Patents

Abstract

【Task】
The reaction of the processing gas in the processing gas supply nozzle is suppressed, the reaction product is prevented from adhering to the processing gas supply nozzle, the generation of particles is suppressed, the product quality is improved, the yield is improved, The maintenance interval for cleaning the processing gas supply nozzle is extended to improve the yield.
[Solution]
A processing chamber 6 for processing the substrate 27; heating means 5 for heating the processing chamber; and a processing gas supply nozzle 11 disposed in the processing chamber for supplying a processing gas into the processing chamber. The nozzle has a heat insulating structure.
[Selection] Figure 1

Description

  The present invention relates to a substrate processing apparatus for performing required processing such as generation of a thin film, diffusion of impurities, and etching on a substrate such as a wafer or a glass substrate.

  One of the processes for manufacturing a semiconductor device is a substrate processing process for performing necessary processes such as thin film formation, impurity diffusion, and etching on a substrate such as a wafer or a glass substrate. In addition, substrate processing apparatuses that perform substrate processing include a single-wafer type substrate processing apparatus that processes substrates one by one and a batch type substrate processing apparatus that processes a predetermined number of substrates at a time. As a processing apparatus, there is a vertical type substrate processing apparatus that includes a vertical processing furnace, and in which a substrate is held in multiple stages in a horizontal posture by a substrate holder (boat) in a processing chamber of the vertical processing furnace.

  In a batch type substrate processing apparatus, processing uniformity between substrates to be processed, for example, wafers, or improvement in yield is required. Further, in order to improve the uniformity of processing, it is required to increase the transport speed of the reaction gas to each wafer and perform high-speed film formation. When supplying the processing gas, the processing gas supplied to the wafer is required. It is necessary to shorten the distance from the supply position to the exhaust. For this reason, in the vertical substrate processing apparatus, a processing gas supply nozzle for supplying a processing gas is provided in the vicinity of the wafer, and the processing gas supply position is close to the wafer, that is, it is high for a wafer at a high position. The nozzle has a height corresponding to the height at which the wafer is accommodated so that the processing gas is supplied from the position.

  For example, Patent Document 1 shows one processing gas supply nozzle having a height that reaches the upper portion of a boat, and the processing gas supply nozzle has gas introduction holes having different opening diameters or numbers depending on the height. In other examples, a plurality of processing gas supply nozzles having different heights are provided, and the plurality of processing gas supply nozzles are uniformly distributed over a plurality of wafers. It is shown that process gas is introduced.

  The conventional processing gas supply nozzle is a single tube nozzle made of quartz and is provided in a processing chamber heated by a heater. Therefore, the processing gas supply nozzle is heated to a high temperature, and the processing gas supply nozzle When the process gas is increased, the process gas is heated in the process of passing through the process gas supply nozzle, the reaction of the process gas is promoted in the process gas supply nozzle, and a reaction product is generated. Deposits and deposits on the inner surface of the processing gas supply nozzle.

  The deposited film formed by adhering deposition is increased in thickness by repeating the film forming process of the wafer, and is easily cracked due to a temperature change or the like in the furnace, and the film is more easily peeled off. Film peeling is a cause of generation of particles, and the generated particles may flow into the processing chamber being processed together with the processing gas, adhere to the wafer, and contaminate the substrate.

  If particles adhere to the wafer, the quality of the process or yield decreases, and in order to prevent the generation of particles, cleaning to remove the deposited film from the inner surface of the process gas supply nozzle is performed periodically, or Must be carried out according to the number of processing times, and the substrate processing apparatus must be stopped during cleaning, resulting in a reduction in operating rate.

Japanese Unexamined Patent Publication No. 7-45529

  In view of such circumstances, the present invention suppresses the reaction of the processing gas in the processing gas supply nozzle, prevents the reaction product from adhering to the processing gas supply nozzle, suppresses the generation of particles, and improves the product quality. The yield is improved by extending the maintenance interval for cleaning the process gas supply nozzle.

  The present invention includes a processing chamber for processing a substrate, heating means for heating the processing chamber, and a processing gas supply nozzle that is disposed in the processing chamber and supplies a processing gas into the processing chamber. The nozzle relates to a substrate processing apparatus having a heat insulating structure.

  According to the present invention, there is provided a processing chamber for processing a substrate, heating means for heating the processing chamber, and a processing gas supply nozzle that is disposed in the processing chamber and supplies a processing gas to the processing chamber. Since the gas supply nozzle has a heat insulating structure, it is suppressed that the processing gas is heated when it flows through the processing gas supply nozzle, and reaction of the processing gas at the processing gas supply nozzle is suppressed. The reaction product is prevented from adhering and depositing on the inner surface of the processing gas supply nozzle, the generation of particles due to the separation of the adhering deposit is prevented, the processing quality of the substrate is improved, and the maintenance interval is extended. As a result, excellent effects such as an improvement in the operating rate of the substrate processing apparatus are exhibited.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  A processing furnace 1 provided in the substrate processing apparatus will be described with reference to FIGS.

  The processing furnace 1 is hermetically connected to a load lock chamber (not shown) which is an airtight chamber.

  A furnace port flange 2 made of a material such as stainless steel is provided in an airtight manner above a decompression hermetic chamber (not shown) such as the load lock chamber, and the furnace port flange 2 forms a furnace port part. An inner tube 3 is concentrically supported at a required position on the inner surface of the furnace port flange 2, and an outer tube 4 is provided at the upper end of the furnace port flange 2 concentrically with the inner tube 3, and further around the outer tube 4. A cylindrical heater 5 serving as a heating means of the processing furnace is provided concentrically with the outer tube 4 so as to surround the outer tube 4.

  The inner tube 3 has a cylindrical shape with an open upper end and a lower end, is made of quartz or silicon carbide, which is heat resistant and does not contaminate the wafer, and stores heat from the heater 5 by storing heat. , Heating to the wafer becomes uniform. The outer tube 4 has a cylindrical cylindrical shape with the lower end opened and the upper end closed, and is made of quartz or silicon carbide like the inner tube 3.

  A reaction tube is constituted by the inner tube 3 and the outer tube 4, and a vertical furnace is constituted by the furnace port flange 2, the inner tube 3, the outer tube 4, the heater 5, and the like. Is a processing chamber 6 for storing a boat 26, which will be described later, and a cylindrical gas exhaust passage 7 is defined between the inner tube 3 and the outer tube 4, and the gas exhaust passage 7 is at the upper end. It communicates with the processing chamber 6.

  A plurality (four in the drawing) of the furnace port flange 2 are airtightly penetrated from the horizontal direction, extend along the inner surface of the inner tube 3 and preferably parallel to the axis of the inner tube 3. Process gas supply nozzles 8, 9, 10, and 11 are provided. The processing gas supply nozzles 8, 9, 10, and 11 are made of quartz, and their upper ends are opened to serve as supply ports. The length (height) of the process gas supply nozzles 8, 9, 10, and 11 is changed in stages, that is, the supply ports of the process gas supply nozzles 8, 9, 10, and 11 are changed in stages. .

  Gas supply pipes 12, 13, 14, 15 pass through the furnace flange 2 in an airtight manner, and the gas supply pipes 12, 13, 14, 15 are connected to the processing gas supply nozzles 8, 9, 10, 11, respectively. Has been.

  The processing gas supply nozzles 8, 9, 10, and 11 have a double-pipe structure, and at least the processing gas supply nozzles 9, 10, and 11 having a vertical portion have a double-pipe structure.

  An example of the processing gas supply nozzles 8, 9, 10, and 11 will be described with reference to FIG. In FIG. 3, the processing gas supply nozzle 11 is representatively shown.

  The processing gas supply nozzle 11 has a heat insulating structure, for example, a double tube structure including an inner tube 16 and an outer tube 17 made of quartz made of a material that does not contaminate the wafer, and the inner tube 16 and the outer tube 17. A space 18 formed by and is an airtight space, and the space 18 is evacuated, and a heat insulating material 19, for example, silica powder (SiO2) is enclosed inside. In particular, silica powder (SiO 2) has a thermal conductivity of about 0.001 to 0.05 W / m · K, and insulates it very effectively. Silica powder (SiO2) is also effective from this point of view because it does not become a contamination source such as organic contamination. Further, glass wool (SiO2) (thermal conductivity of about 0.036 to 0.045 W / m · K) or the like can provide the same effect. The space 18 may be kept in a vacuum state without sealing a heat insulating material. When sealing in a vacuum state, a vacuum close to 0 Pa can be obtained by sealing after exhausting the space 18 while baking the processing gas supply nozzle at 600 ° C., and preferably in such a vacuum state If this is the case, the heat insulation effect is enhanced, but at least the processing gas supply nozzle is inserted into the processing chamber and the processing chamber is supplied with the processing gas from the processing gas supply nozzle. The effect is obtained.

  The furnace port flange 2 is provided with an exhaust pipe 21 communicating with the lower end portion of the gas exhaust path 7. The processing gas introduced from the processing gas supply nozzles 8, 9, 10, and 11 ascends the processing chamber 6, turns back at the upper end of the inner tube 3, descends the gas exhaust path 7, and the processed gas is It is exhausted from the exhaust pipe 21.

  A lower end opening (furnace port) of the furnace port flange 2 is hermetically closed by a seal cap 22, and the seal cap 22 is supported by a boat elevator 23 so as to be movable up and down. The boat elevator 23 serves as boat loading / unloading means for moving the boat 26 up and down and loading and unloading it into the processing chamber 6.

  The seal cap 22 is provided with a boat rotating device 24, and a boat 26, which is a substrate holder, is erected on a boat receiving table 25 rotated by the boat rotating device 24. The boat 26 holds the wafers 27 in a horizontal posture in multiple stages, and is made of a material such as quartz that does not contaminate the wafers 27.

  The gas supply pipes 12, 13, 14, and 15 are provided with flow controllers 28, 29, 30, and 31, and the processing gas supply nozzles 8, 9, 10, and 11 are connected to the flow controllers 28, 29, 30, and 31, respectively. 31 is connected to a processing gas supply source (not shown) for supplying a processing gas such as SiH4 or a purge gas supply source (not shown) for supplying an inert gas such as nitrogen gas.

  The processing state of the wafer 27 processed in the processing furnace 1 is controlled by the main control unit 33. The main control unit 33 includes a temperature control unit 34 for controlling the temperature in the processing furnace 1, a gas flow rate control unit 35 for controlling the flow rate of the processing gas, a pressure control unit 36 for controlling the pressure in the outer tube 4, A drive control unit 37 that controls drive units of the boat rotating device 24, the boat elevator 23, and the like is provided.

  One or more temperature detectors 38 are provided between the inner tube 3 and the outer tube 4, and the temperature detector 38 detects the temperature in the outer tube 4. A temperature detection signal is input from the temperature detector 38, and the temperature control unit 34 controls the heater 5 to uniformly heat the inside of the furnace.

  The flow rate controllers 28, 29, 30, and 31 are controlled by the gas flow rate control unit 35, and control the process gas supplied from the process gas supply nozzles 8, 9, 10, and 11 to a required gas flow rate. . The exhaust pipe 21 is provided with a pressure detector 39, the exhaust pipe 21 is connected to an exhaust device 42 via an exhaust line 41, and the exhaust line 41 is provided with a pressure control valve 43. The exhaust pressure is detected by the pressure detector 39, and the detected pressure detection signal is input to the pressure control unit 36, which controls the pressure control valve 43 to control the pressure in the processing chamber 6. Take control.

  Hereinafter, the operation will be described.

  The boat 26 is lowered by the boat elevator 23, and the wafer 27 is transferred to the lowered boat 26 by a substrate transfer machine (not shown). With a predetermined number of wafers 27 loaded, the boat elevator 23 raises the seal cap 22 and loads the boat 26 into the processing chamber 6. The processing chamber 6 is hermetically closed by the seal cap 22, and is reduced to a processing pressure by the exhaust device 42 through the exhaust pipe 21, and the processing chamber 6 is heated to a processing temperature by the heater 5. Further, the boat rotating device 24 rotates the boat 26 around the vertical axis, and is controlled by the drive control unit 37 so that the rotational speed is maintained at a predetermined speed.

  The flow rate controllers 28, 29, 30, 31 control the flow rate of the processing gas (SiH 4) according to a command from the gas flow rate control unit 35, and the processing gas is supplied from the processing gas supply nozzles 8, 9, 10, 11. It is supplied to the processing chamber 6.

  In the process in which the processing gas rises in the processing chamber 6, reaction products are deposited on the wafer 27 by a thermal reaction, and a film is formed. Further, since the boat 26 is rotated, the drift of the processing gas to the wafer 27 is prevented, and the processing is made uniform.

  Further, the processing gas is consumed by the film formation, but the upper end positions (gas introduction positions) of the processing gas supply nozzles 8, 9, 10, and 11 are opened upward stepwise, so that the consumption amount is reduced. The processing gas is sequentially introduced so as to supplement, and the processing gas is introduced at a uniform concentration from the lower part to the upper part of the processing chamber 6. Therefore, the film thickness in the wafer 27 surface is made uniform.

  The flow rate controllers 28, 29, 30, and 31 control the gas supply amounts from the process gas supply nozzles 8, 9, 10, and 11 so that the gas concentration of the process gas becomes constant.

  The processing gas passes through the processing gas supply nozzles 8, 9, 10, and 11 and is heated by the heater 5 in the process of rising. For this reason, in the process which passes the said process gas supply nozzles 8, 9, 10, and 11, especially the process gas supply nozzles 9, 10, and 11 which have a perpendicular | vertical part, it is easy to heat. Since the processing gas supply nozzles 9, 10, and 11 have the heat insulating structure as described above, the reaction of the processing gas is suppressed. Therefore, the reaction product is prevented from being deposited on the inner surfaces of the processing gas supply nozzles 8, 9, 10, and 11.

  Therefore, even when the film forming process is repeated, the amount of reaction product deposited on the process gas supply nozzles 8, 9, 10, and 11 can be reduced, and the process gas supply nozzles 8, 9, 10, and 11 can be reduced. Particle generation due to peeling of the deposited film generated on the inner surface can be suppressed, and high-quality substrate processing can be performed. Further, the interval between the cleaning times of the process gas supply nozzles 8, 9, 10, and 11 can be increased, and the operating rate of the substrate processing apparatus can be improved.

  When the film forming process is completed, the processing chamber 6 is replaced with an inert gas, the processing chamber 6 is brought to normal pressure or equalized with the load lock chamber, and the boat 26 is lowered by the boat elevator 23. The

  The processed wafer 27 of the boat 26 is replaced with an unprocessed wafer by a substrate transfer machine (not shown). The boat 26 loaded with unprocessed wafers is loaded into the processing chamber 6 by the boat elevator 23, and substrate processing is repeated.

  The process chamber is heated to the process temperature by the heater before flowing the process gas to the process gas supply nozzle so that the inert gas is continuously supplied, and the inert gas is switched to the process gas during the process. When the processing chamber is heated to the processing temperature by the heater by switching to the inert gas again after the processing is completed, the gas is circulated in the processing gas supply nozzle as much as possible at least at a temperature lower than the processing temperature. The inside of the processing gas supply nozzle is kept at a low temperature by the supplied gas, and generation of particles in the processing gas supply nozzle can be further suppressed.

  4 and 5 show other examples of the processing gas supply nozzles 8, 9, 10, and 11. FIG. In the processing gas supply nozzles 9, 10, and 11, the plurality of gas supply ports 45a, 45b, 45c, 45d, 45e, and 45f are connected to the processing gas supply nozzles 9, 10, and 11 so that the distributed supply of the processing gas is further promoted. These are provided on the side surface of the plate at a required interval in the height direction.

  The processing gas supply nozzles 9, 10, 11 also have a double tube structure of an inner tube 16 and an outer tube 17, and an airtight space 18 is provided between the inner tube 16 and the outer tube 17. And a heat insulating material 19 is enclosed in the space 18.

  In the processing gas supply nozzles 9, 10, and 11 shown in FIGS. 4 and 5, the processing gas is dispersed and supplied to the processing chamber 6 from a plurality of gas supply ports 45a, 45b, 45c, 45d, 45e, and 45f. , Process uniformity between wafers is improved.

  In the above embodiment, an example in which the processing gas supply nozzles 9, 10, and 11 extending in the vertical direction have a heat insulating structure is shown. Needless to say, it may be applied to piping for gas supply.

  The heat insulating material 19 enclosed in the space 18 of the processing gas supply nozzles 8, 9, 10, 11 is silica powder (SiO2), the temperature at the time of film formation is 530 ° C., the processing gas is SiH4, PH3 (processing gas flow rate 1600 (sccm ) / 200 (sccm)) at a processing pressure of 300 Pa, a high-speed film forming process using D-Poly, and Depo. FIG. 6 shows the state of generation of particles when the rate is 50 Å / min.

  When the processing gas supply nozzle having the conventional structure is used, 175 particles are generated when the particle diameter is 0.18 μm or more, whereas when the processing gas supply nozzle according to the present invention is used, the number is reduced to 14. The generation of particles can be suppressed by using the processing gas supply nozzle having a heat insulating structure.

  As other processing, it is applicable to processing Si3 N4, for example, under the conditions of a wafer temperature of 740 ° C., a processing gas of DCS, NH3, a gas flow rate of 30/150 (sccm), and a processing pressure of 30 Pa. To be implemented.

(Appendix)
The present invention includes the following embodiments.

  (Supplementary Note 1) A processing chamber for processing a substrate, a heating means for heating the processing chamber, and a processing gas supply nozzle that is disposed in the processing chamber and supplies a processing gas into the processing chamber. The nozzle has a heat insulating structure.

  (Supplementary note 2) The substrate processing apparatus according to supplementary note 1, wherein the processing gas supply nozzle has a double tube structure including an inner tube and an outer tube, and a vacuum is formed between the inner tube and the outer tube.

  (Supplementary note 3) The substrate processing apparatus according to supplementary note 1, wherein the processing gas supply nozzle has a double tube structure including an inner tube and an outer tube, and a heat insulating material is sealed between the inner tube and the outer tube.

  (Supplementary Note 4) A processing chamber for processing a substrate, a heating unit for heating the processing chamber, and a processing gas supply nozzle that is disposed in the processing chamber and supplies a processing gas into the processing chamber. The nozzle is a method of manufacturing a semiconductor device using a substrate processing apparatus having a heat insulation structure, the step of heating the processing chamber by a heating means, and a processing gas to the processing chamber via the processing gas supply nozzle And a process for processing the substrate in the processing chamber.

It is a general | schematic front sectional view which shows embodiment of this invention. It is a schematic sectional side view which shows embodiment of this invention. It is an expanded sectional view of the process gas supply nozzle used for this embodiment. It is an expanded sectional view of the other process gas supply nozzle used for this embodiment. It is an upper end part enlarged view of this other process gas supply nozzle. It is a graph which shows the particle generation state in this invention, and the particle generation state in a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Processing furnace 5 Heater 6 Processing chamber 7 Gas exhaust path 8, 9, 10, 11 Processing gas supply nozzle 16 Inner pipe 17 Outer pipe 18 Space 19 Heat insulating material 23 Boat elevator 24 Boat rotation apparatus 26 Boat 27 Wafer 28, 29, 30 , 31 Flow rate controller 33 Main controller 38 Temperature detector 39 Pressure detector 41 Exhaust line

Claims (1)

  A processing chamber for processing the substrate; heating means for heating the processing chamber; and a processing gas supply nozzle that is disposed in the processing chamber and supplies a processing gas to the processing chamber. A substrate processing apparatus having a structure.

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