JP2007005581A - Substrate processing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable several kinds of wafers to be processed simultaneously and improved in processing quality in batch processing. <P>SOLUTION: A substrate processing device is equipped with a reaction tube 2 processing substrates, a heater 10 heating the substrates in the reaction tube, and a substrate holder 16 which holds a required number of the substrates in the reaction tube 2. The substrate holder 16 holds two or more kinds of substrates and is equipped with wafer holding regions corresponding to the kinds of the substrates, and substrate supporting parts holding the substrate are configured so as to be different from each other in space between them and/or shape for each wafer holding region. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a substrate processing apparatus for forming a thin film on a substrate such as a silicon wafer by a CVD process or performing a substrate process such as an impurity diffusion process or an annealing process.

  In the process of manufacturing a semiconductor device by processing a substrate such as a silicon wafer (quartz wafer, Si wafer, SiC wafer, etc.), a CVD process film generation process or oxide film generation process, impurity diffusion process on the substrate surface Or substrate processing such as annealing.

  Substrate processing apparatuses that perform substrate processing include a single-wafer type that processes one by one and a batch type that processes a predetermined number of sheets at a time. The batch-type substrate processing apparatus includes a processing furnace, and the processing furnace includes A predetermined number of wafers are stored and processed. In the processing furnace, the substrates are held in multiple stages in a horizontal posture by a substrate holder (hereinafter referred to as a boat).

  When a film processing is performed on a wafer with a substrate processing apparatus, the material of the wafer to be processed is usually one of quartz wafer, Si wafer, SiC wafer, etc., and the form in which the boat holds the wafer is simply the entire boat. It was a form. That is, the wafer holding interval in the boat is the same, and the shape of the wafer holding portion of the boat is also the same.

  However, the diversification of customer demands in recent years has led to the simultaneous processing of a plurality of types of wafers even in a batch type substrate processing apparatus.

  There are cases where plural types of wafers, for example, wafers of different types and materials, or wafers of different plate thicknesses are mixed and processed in a processing furnace.

  When wafers having the same holding interval and the same shape of the wafer holding portion and different types of wafers are processed, there are cases where the wafers cannot be processed properly.

  For example, when Si wafers and quartz wafers with different plate thicknesses are simultaneously held by a boat and heat-treated, the Si wafers and quartz wafers have different plate thicknesses and thermal expansions. In some cases, the part contacts the upper wafer holding part to generate scratches, and at the same time, particles are generated, leading to deterioration in processing quality.

  Furthermore, even when processing a single type of wafer, the gas flow rate and the film forming temperature are different at the position of the wafer in the furnace, and not all wafers to be batch processed can be processed uniformly.

  In view of such a situation, the present invention intends to simultaneously process a plurality of types of wafers in batch processing to improve processing quality.

  The present invention includes a reaction tube for processing a substrate, a heater for heating the substrate in the reaction tube, and a substrate holder for holding a required number of substrates in the reaction tube, and the substrate holder has at least two kinds. A substrate processing apparatus configured to hold the above substrates and have a wafer holding region corresponding to each type of substrate, and the intervals or / and shapes of the substrate support portions for supporting the substrates differ for each wafer holding region. It is related to.

  According to the present invention, there is provided a reaction tube for processing a substrate, a heater for heating the substrate in the reaction tube, and a substrate holder for holding a required number of substrates in the reaction tube, and the substrate holder is at least Since it holds two or more types of substrates, it has a wafer holding area corresponding to each type of substrate, and each wafer holding area is configured so that the interval or / and the shape of the substrate support part supporting the substrate are different. The excellent effect of avoiding contact with other parts of the boat due to warpage occurring during the processing of each of the various substrates, suppressing the generation of particles, and improving the processing quality when processing multiple substrates simultaneously. Demonstrate.

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

  First, an outline of a substrate processing apparatus in which the present invention is implemented will be described with reference to FIG.

  A heater 10 serving as a heating means is erected on the heater base 21, and a silicon carbide soaking tube 1 is concentrically housed in the heater 10, and a silicon carbide or quartz reaction tube 2 is contained in the soaking tube 1. Arranged concentrically, the reaction tube 2 accommodates the wafer 17 and defines a processing chamber 19 for processing the wafer 17. Note that two or more types of wafers 17 to be processed in the processing chamber 19 are simultaneously processed among quartz wafers, Si wafers, SiC wafers, and the like.

  An inlet 5 is attached to the lower end of the reaction tube 2, and the inlet 5 is connected to a processing gas supply source (not shown) or an inert gas (purge gas) supply source such as nitrogen gas via a gas supply pipe 3. The gas supply pipe 3 is connected to a flow rate control means, for example, a mass flow controller 22. An exhaust port 9 communicates with the lower end portion of the reaction tube 2, and the exhaust port 9 is connected to an exhaust device (not shown) via a gas exhaust tube 4. The gas exhaust tube 4 has a pressure sensor 23 and a pressure adjustment. A vessel 24 is provided.

  A conduit 6 communicates with the introduction port 5, the conduit 6 rises along the outer surface of the reaction tube 2, communicates with a gas reservoir 7 provided on the upper end surface of the reaction tube 2, and the gas reservoir The part 7 communicates with the processing chamber 19 through the dispersion hole 8.

  A silicon carbide or quartz boat 16 can be loaded into and withdrawn from the processing chamber 19. The boat 16 is placed on a seal cap 13 via a boat cap 15 and a base 12. 13 can airtightly close the open bottom surface of the reaction tube 2. The seal cap 13 is supported by a boat elevator 18, and the boat elevator 18 can raise and lower the boat cap 15 and the boat 16 through the seal cap 13, and the boat 16 is mounted in the processing chamber 19 by raising and lowering. It is possible to remove.

  The boat cap 15 is rotatable with respect to the base 12, and the boat cap 15 is rotatable by a rotating means 14.

  In FIG. 1, reference numeral 25 denotes a main control unit, and the main control unit 25 includes a temperature control unit 26, a gas flow rate control unit 27, a drive control unit 28, and a pressure control unit 29.

  A detection result from the thermocouple 11 that detects the temperature of a required location in the furnace is input to the temperature control unit 26, and the temperature control unit 26 sets the processing chamber 19 to a predetermined temperature, for example, a process temperature based on the temperature detection result. The heater 10 is controlled so that The gas flow rate control unit 27 controls the reaction gas introduced from the introduction port 5 to a predetermined flow rate, and the pressure control unit 29 is based on the pressure input from the pressure sensor 23. To control the pressure in the processing chamber 19 to a predetermined pressure, for example, a process pressure.

  The drive control unit 28 controls the rotating means 14 to rotate the boat 16 being processed at a predetermined rotational speed, and controls the boat elevator 18 to raise and lower the boat 16.

  Hereinafter, an example of substrate processing, for example, oxidation / diffusion processing will be described.

  The boat elevator 18 is driven to lower the boat 16.

  A predetermined number of wafers 17 are transferred onto the boat 16 by a wafer transfer machine (not shown). The reaction tube 2 is heated by the heater 10 through the soaking tube 1, and the temperature of the processing chamber 19 is determined based on the temperature of the processing chamber 19 detected by the thermocouple 11. Controlled to ° C. The processing chamber 19 is previously filled with an inert gas by being supplied with an inert gas from the inlet 5 and the conduit 6.

  The boat 16 loaded with unprocessed wafers 17 is loaded into the reaction tube 2 by the boat elevator 18. In the loaded state of the boat 16, the base 12 airtightly closes the lower end opening of the reaction tube 2. While the temperature of the processing chamber 19 is raised to, for example, about 750 to 800 ° C. as the processing temperature, the pressure of the processing chamber 19 is maintained at the processing pressure, for example, 750 Torr to 760 Torr based on the detected pressure of the pressure sensor 23. The

  The rotating means 14 is driven, and the wafer 17 is rotated through the boat 16. At the same time, water vapor is supplied from the gas supply pipe 3 from a reaction gas or a moisture generator (not shown). The supplied reaction gas or water vapor descends the reaction tube 2 from the gas reservoir 7 through the dispersion hole 8 and is evenly supplied to the wafer 17 to perform the required processing of oxidation and diffusion. The The pressure in the processing chamber 19 during the oxidation / diffusion process is controlled by the pressure regulator 24 so that the exhaust gas is exhausted through the gas exhaust pipe 4 and reaches a predetermined pressure.

  When the substrate processing is completed, the processing chamber 19 is purged with an inert gas, the boat elevator 18 is lowered by the boat elevator 18, and the processed wafers 17 are discharged.

  Unprocessed wafers 17 are transferred to the empty boat 16 and the above processing is repeated.

As an example, the processing conditions of the substrate processed in the present invention are as follows. In the annealing process, the wafer temperature is 1200 ° C., the gas species supply amount is Ar gas, 10 m ³ / min, and the processing pressure is 755 Torr.

  Next, referring to FIG. 2, the wafer support 30 of the boat 16 will be described. In the following description, it is assumed that the wafers 17 to be processed are the Si wafer 17a and the quartz wafer 17b.

  In FIG. 2, the upper portion of the boat 16 shows a Si wafer holding region 31 and the lower portion shows a quartz wafer holding region 32.

  When the materials of Si and quartz are compared, Si has a larger coefficient of thermal expansion than quartz, and the Si wafer 17a is thinner than the quartz wafer 17b. Because of these differences in material shape, the Si wafer 17a has a large warp when heated with respect to the quartz wafer 17b. For example, with respect to the Si wafer 17a, the difference in warpage between the central portion and the peripheral portion is about 5 mm in a wafer having a diameter of 300 mm. As for the quartz wafer 17b, the difference in warpage between the central portion and the peripheral portion is about 1 mm or less in a wafer having a diameter of 300 mm.

  The substrate holding interval G1 in the Si wafer holding region 31 with a large amount of warpage is made larger than the substrate holding interval G2 in the quartz wafer holding region 32, and each substrate holding interval G1 and substrate holding interval G2 is set to the Si wafer 17a, The quartz wafer 17b is set larger than the warp amount when the quartz wafer 17b is warped to the maximum. As an allowance, a gap of about 1 mm is formed from the curved peripheral edge.

  The difference between the substrate holding interval G1 and the substrate holding interval G2 is set in consideration of the material and diameter of the wafer. In the example of the wafer having a diameter of 300 mm, for example, the substrate holding interval G1 is set to 8.5 mm. The substrate holding interval G2 is set to 7.5 mm.

  As a method of changing the substrate holding interval G1 and the substrate holding interval G2, the pitch at which the wafer support portions 30 are provided is changed, or the thickness of the wafer support portions 30 is changed. Alternatively, a method of changing the pitch and changing the thickness is adopted.

  In FIG. 2, the thickness of the wafer support 30a for supporting the Si wafer 17a is reduced, the thickness of the wafer support 30b for supporting the quartz wafer 17b is increased, and the pitch of the wafer support 30 is changed to the Si wafer holding area. 31 and the quartz wafer holding region 32 are changed so that a gap of the substrate holding interval G1 and the substrate holding interval G2 is obtained.

  As in the present invention, the Si wafer 17a and the quartz wafer 17b are mixed and processed by preventing the wafer periphery from coming into contact with the upper wafer support 30 due to the warpage of the wafer during processing. The amount of particles generated is greatly reduced.

  FIG. 3 shows a comparison between the case where the Si wafer 17a and the quartz wafer 17b are mixed and processed by the conventional substrate processing apparatus and the case where the Si wafer 17a and the quartz wafer 17b are mixed and processed in the present invention. In the processing by the substrate processing apparatus according to the present invention, the generation amount of particles is greatly reduced and the uniformity of the film thickness is improved, and the substrate holding interval G1 and the substrate holding interval G2 are changed. It is shown that there is no adverse effect on the wafer processing quality.

  Further, the warpage state of the wafer 17 also changes depending on the number of the wafer support portions 30 that support the wafer 17 and the position of the wafer support portion 30. Therefore, the substrate holding interval G1 and the substrate holding interval G2 may be set in consideration of changes in the number and position of the wafer support portions 30.

  In the above embodiment, the upper portion of the boat 16 is the Si wafer holding region 31 and the lower portion is the quartz wafer holding region 32. Conversely, the upper portion is the quartz wafer holding region 32 and the lower portion is the Si wafer holding region 31. It is good. Further, how to set the holding area, such as the Si wafer holding area 31 or the quartz wafer holding area 32, may be appropriately set according to the processing substrate.

  In addition, it is known that there is a dependency relationship between the wafer interval and the film thickness uniformity, and in order to improve the film quality uniformity formed on the same type of substrate, the wafer depends on the position of the wafer holding region. The interval may be changed.

(Appendix)
The present invention includes the following embodiments.

  (Additional remark 1) It has a reaction tube which processes a substrate, a heater which heats a substrate in the reaction tube, and a substrate holder which holds a required number of substrates in the reaction tube, and there are at least two kinds of the substrate holders In addition to holding the above-mentioned substrates, it has a wafer holding region corresponding to each type of substrate, and the interval or / and the shape of the substrate support part for supporting the substrate is different for each wafer holding region. A substrate processing apparatus.

  (Supplementary note 2) The substrate processing apparatus according to supplementary note 1, wherein the two or more types of substrates are substrates of at least two or more different materials selected from the group consisting of quartz, silicon, and silicon carbide.

  (Supplementary note 3) The substrate processing apparatus according to supplementary note 1, wherein the shape of the substrate support portion is a thickness of the substrate support portion.

  (Additional remark 4) The said board | substrate holder has the 1st area | region which hold | maintains the board | substrate of 1st material or thickness, and the 2nd area | region which hold | maintains the board | substrate of 2nd material or thickness, The substrate processing apparatus according to supplementary note 1, wherein the first region and the second region are configured so that a distance or / and a shape of a support portion supporting a substrate are different.

  (Supplementary note 5) The substrate processing apparatus according to supplementary note 4, wherein the first material is silicon and the second material is quartz.

  (Supplementary note 6) The substrate processing apparatus according to supplementary note 5, wherein an interval between the support portions in the first region is larger than an interval between the support portions in the second region.

  (Supplementary note 7) The substrate processing apparatus according to Supplementary note 5 or 6, wherein the thickness of the support portion in the first region is thinner than the thickness of the support portion in the second region.

  (Supplementary note 8) A method for manufacturing a semiconductor device, comprising using the substrate processing apparatus of supplementary note 1 to process at least two kinds of substrates made of different materials or thicknesses in the same reaction chamber at a time.

1 is an elevational sectional view showing a substrate processing apparatus according to an embodiment of the present invention. It is explanatory drawing which shows a part of boat in this substrate processing apparatus. It is a figure which shows the processing state of the board | substrate when processed with the substrate processing apparatus which concerns on embodiment of this invention, and the processing state of the board | substrate when processed with the conventional substrate processing apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Soaking tube 2 Reaction tube 10 Heater 16 Boat 17 Wafer 17a Si wafer 17b Quartz wafer 19 Processing chamber 30 Wafer support part 31 Si wafer holding area 32 Quartz wafer holding area

Claims (1)

  A reaction tube that processes the substrate; a heater that heats the substrate in the reaction tube; and a substrate holder that holds a required number of substrates in the reaction tube. The substrate holder includes at least two kinds of substrates. The substrate processing is characterized in that it has a wafer holding area corresponding to each type of substrate and is configured such that the interval or / and the shape of the substrate support portion for supporting the substrate is different for each wafer holding area. apparatus.

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