CN116364640A - Tray for insulating film forming apparatus, and insulating film forming method - Google Patents
Tray for insulating film forming apparatus, and insulating film forming method Download PDFInfo
- Publication number
- CN116364640A CN116364640A CN202211508009.4A CN202211508009A CN116364640A CN 116364640 A CN116364640 A CN 116364640A CN 202211508009 A CN202211508009 A CN 202211508009A CN 116364640 A CN116364640 A CN 116364640A
- Authority
- CN
- China
- Prior art keywords
- insulating film
- tray
- semiconductor wafer
- wafer
- diameter
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims description 20
- 239000004065 semiconductor Substances 0.000 claims abstract description 276
- 230000015572 biosynthetic process Effects 0.000 claims abstract description 61
- 235000012431 wafers Nutrition 0.000 claims description 421
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical group [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 64
- 229910052710 silicon Inorganic materials 0.000 claims description 64
- 239000010703 silicon Substances 0.000 claims description 64
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 48
- 239000000463 material Substances 0.000 claims description 22
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 claims description 18
- 229910010271 silicon carbide Inorganic materials 0.000 claims description 18
- 239000010453 quartz Substances 0.000 claims description 14
- 239000002994 raw material Substances 0.000 claims description 12
- 239000007789 gas Substances 0.000 description 162
- 230000002093 peripheral effect Effects 0.000 description 68
- 239000011261 inert gas Substances 0.000 description 56
- 229910052814 silicon oxide Inorganic materials 0.000 description 34
- 230000000694 effects Effects 0.000 description 13
- 238000005259 measurement Methods 0.000 description 7
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 6
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 6
- 229910052581 Si3N4 Inorganic materials 0.000 description 6
- 230000000052 comparative effect Effects 0.000 description 6
- 150000004767 nitrides Chemical class 0.000 description 6
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 6
- 238000010586 diagram Methods 0.000 description 5
- 230000003247 decreasing effect Effects 0.000 description 4
- 230000000149 penetrating effect Effects 0.000 description 4
- 238000005245 sintering Methods 0.000 description 4
- JBRZTFJDHDCESZ-UHFFFAOYSA-N AsGa Chemical compound [As]#[Ga] JBRZTFJDHDCESZ-UHFFFAOYSA-N 0.000 description 3
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 3
- 229910001218 Gallium arsenide Inorganic materials 0.000 description 3
- BLRPTPMANUNPDV-UHFFFAOYSA-N Silane Chemical compound [SiH4] BLRPTPMANUNPDV-UHFFFAOYSA-N 0.000 description 3
- 229910021529 ammonia Inorganic materials 0.000 description 3
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 3
- 230000000740 bleeding effect Effects 0.000 description 3
- 238000011156 evaluation Methods 0.000 description 3
- GNPVGFCGXDBREM-UHFFFAOYSA-N germanium atom Chemical compound [Ge] GNPVGFCGXDBREM-UHFFFAOYSA-N 0.000 description 3
- 239000012535 impurity Substances 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 229910052757 nitrogen Inorganic materials 0.000 description 3
- 239000001301 oxygen Substances 0.000 description 3
- 229910052760 oxygen Inorganic materials 0.000 description 3
- 229910000077 silane Inorganic materials 0.000 description 3
- 238000005229 chemical vapour deposition Methods 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- 229910052756 noble gas Inorganic materials 0.000 description 2
- 150000002835 noble gases Chemical class 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 238000001505 atmospheric-pressure chemical vapour deposition Methods 0.000 description 1
- 239000012159 carrier gas Substances 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- MROCJMGDEKINLD-UHFFFAOYSA-N dichlorosilane Chemical compound Cl[SiH2]Cl MROCJMGDEKINLD-UHFFFAOYSA-N 0.000 description 1
- 239000002019 doping agent Substances 0.000 description 1
- 230000005669 field effect Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000003384 imaging method Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- QPJSUIGXIBEQAC-UHFFFAOYSA-N n-(2,4-dichloro-5-propan-2-yloxyphenyl)acetamide Chemical compound CC(C)OC1=CC(NC(C)=O)=C(Cl)C=C1Cl QPJSUIGXIBEQAC-UHFFFAOYSA-N 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- ZDHXKXAHOVTTAH-UHFFFAOYSA-N trichlorosilane Chemical compound Cl[SiH](Cl)Cl ZDHXKXAHOVTTAH-UHFFFAOYSA-N 0.000 description 1
- 239000005052 trichlorosilane Substances 0.000 description 1
- RUDFQVOCFDJEEF-UHFFFAOYSA-N yttrium(III) oxide Inorganic materials [O-2].[O-2].[O-2].[Y+3].[Y+3] RUDFQVOCFDJEEF-UHFFFAOYSA-N 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/67—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
- H01L21/683—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for supporting or gripping
- H01L21/687—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for supporting or gripping using mechanical means, e.g. chucks, clamps or pinches
- H01L21/68714—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for supporting or gripping using mechanical means, e.g. chucks, clamps or pinches the wafers being placed on a susceptor, stage or support
- H01L21/68735—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for supporting or gripping using mechanical means, e.g. chucks, clamps or pinches the wafers being placed on a susceptor, stage or support characterised by edge profile or support profile
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/02002—Preparing wafers
- H01L21/02005—Preparing bulk and homogeneous wafers
- H01L21/02008—Multistep processes
- H01L21/0201—Specific process step
- H01L21/02016—Backside treatment
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Manufacturing & Machinery (AREA)
- Computer Hardware Design (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Power Engineering (AREA)
- Container, Conveyance, Adherence, Positioning, Of Wafer (AREA)
- Chemical Vapour Deposition (AREA)
- Formation Of Insulating Films (AREA)
Abstract
The invention provides a tray for an insulating film forming device, which can inhibit the formation of an insulating film on the outer periphery of a semiconductor wafer and form the insulating film on the back surface of the semiconductor wafer. The invention is a tray (1) for placing a semiconductor wafer on an insulating film forming device for forming an insulating film on the back surface of the semiconductor wafer, characterized in that the tray is provided with a tray main body (11) for placing the semiconductor wafer, the tray main body (11) is provided with a concave part (11 c) and an annular groove (11 d), the concave part (11 c) is arranged on the upper surface (11 a) of the tray main body (11) for accommodating the semiconductor wafer, the concave part (11 c) is cylindrical, the annular groove (11 d) is arranged in the concave part (11 c), the inner diameter is smaller than the diameter of the semiconductor wafer, and the outer diameter is larger than the diameter of the semiconductor wafer.
Description
Technical Field
The invention relates to a tray for an insulating film forming apparatus, and an insulating film forming method.
Background
In recent years, in various semiconductor devices such as MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistor), DRAM (Dynamic Random Access Memory), power transistors, and back-illuminated solid-state imaging devices, an epitaxial wafer having an epitaxial layer of silicon or the like formed on a semiconductor wafer such as a silicon wafer is generally used as a substrate.
For example, an epitaxial silicon wafer can be obtained by: a silicon wafer is placed in a blade-type epitaxial growth furnace, and a raw material gas such as dichlorosilane gas or trichlorosilane gas is supplied into the epitaxial growth furnace together with a carrier gas such as hydrogen gas to grow a silicon epitaxial layer on the silicon wafer.
However, in the case of forming an epitaxial layer having a high resistivity on a semiconductor wafer having a low resistivity, so-called self-doping tends to occur in which a dopant in the semiconductor wafer flies out from the back surface of the semiconductor wafer or the like into the gas phase and enters the epitaxial layer. Therefore, the following steps are performed before the growth of the epitaxial layer: an insulating film such as an oxide film is formed on the back surface of a semiconductor wafer as a protective film for suppressing self-doping (for example, refer to patent document 1).
The insulating film can be formed by, for example, chemical vapor deposition (Chemical Vapor Deposition, CVD). For example, in an atmospheric pressure CVD method in which CVD is performed at atmospheric pressure, after a semiconductor wafer is placed on a tray with the surface (i.e., the back surface) on which an insulating film is formed facing upward, a source gas for the insulating film is supplied to the semiconductor wafer in a state where the semiconductor wafer has been heated, whereby an insulating film is formed on the back surface of the semiconductor wafer.
In the above conventional method, since the source gas of the insulating film is wound around the outer edge of the front surface of the wafer, the insulating film is formed so as to pass from the back surface of the semiconductor wafer to the outer edge of the wafer end surface and the front surface of the semiconductor wafer. On the other hand, when an epitaxial layer is formed on a semiconductor wafer in which an insulating film is formed on the wafer outer peripheral portion extending from the outer edge of the back surface to the outer edge of the wafer end surface and the front surface, cracks may occur on the wafer outer peripheral portion, and the epitaxial layer may grow abnormally, so-called nodules may occur. Therefore, in the case where an insulating film is formed on the back surface of the wafer by the conventional method, the insulating film formed on the outer peripheral portion of the wafer is removed thereafter. The insulating film on the outer periphery of the wafer can be removed by wiping with a nozzle that is impregnated with a removing liquid such as hydrofluoric acid (HF) liquid.
Patent document 1: international publication No. 2011/070741.
In the removal of the insulating film on the wafer outer periphery by the wiping method, there are cases where the removing liquid may infiltrate into not only the insulating film on the wafer outer periphery but also a part of the insulating film on the wafer back surface, which is called "bleeding". If such bleeding occurs, the semiconductor wafer becomes defective and cannot be used as a substrate for an epitaxial wafer. Therefore, it is necessary to form an insulating film again after temporarily removing the formed insulating film, and there is a problem that productivity is lowered.
In order to suppress the occurrence of the bleeding as described above, it is preferable to suppress the formation of the insulating film toward the outer peripheral portion of the wafer.
Disclosure of Invention
The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a tray for an insulating film forming apparatus capable of forming an insulating film on a back surface of a semiconductor wafer while suppressing the formation of the insulating film on the outer peripheral portion of the semiconductor wafer.
The present invention to solve the above problems is as follows.
[1] A tray for an insulating film forming apparatus for placing a semiconductor wafer on an insulating film forming apparatus for forming an insulating film on a rear surface of the semiconductor wafer, characterized by comprising a tray body for placing the semiconductor wafer, wherein the tray body has a recess provided on an upper surface of the tray body for accommodating the semiconductor wafer recess, and an annular groove provided in the recess, the annular groove having an inner diameter smaller than a diameter of the semiconductor wafer and an outer diameter larger than the diameter of the semiconductor wafer.
[2] The tray for an insulating film forming apparatus according to [1], wherein the tray main body is provided with a low heat conduction member in the annular groove, and the low heat conduction member is made of a material having a lower heat conductivity than a material constituting the tray main body.
[3] The tray for an insulating film formation apparatus according to [1] or [2], wherein the low heat conductive member is constituted by a ring-shaped member or a plurality of block-shaped members.
[4] The tray for an insulating film formation apparatus according to any one of the above [1] to [3], wherein the tray main body is made of silicon carbide, and the low heat conductive member is made of quartz.
[5] The tray for an insulating film formation apparatus according to any one of the above [1] to [4], wherein a difference between an inner diameter of the annular groove and a diameter of the semiconductor wafer is 10mm to 20mm, and a difference between an outer diameter of the annular groove and a diameter of the semiconductor wafer is 1mm to 16 mm.
[6] The tray for an insulating film formation apparatus according to any one of the above [3] to [5], wherein a width of the annular member is smaller than a width of the annular groove, and a difference between the width of the annular member and the width of the annular groove is 1mm to 2 mm.
[7] An insulating film forming apparatus for forming an insulating film on a back surface of a semiconductor wafer, comprising a source gas supply unit, a heater, and the tray according to any one of [1] to [6], wherein the source gas supply unit is disposed above the tray, supplies source gas of the insulating film to the back surface of the semiconductor wafer placed on the tray, and the heater is disposed below the tray, and heats the semiconductor wafer.
[8] The insulating film forming apparatus according to item [7] above, wherein the insulating film forming apparatus comprises a plurality of trays, and a transport roller is provided at a lower portion of the tray main body, and the plurality of trays are transported between the source gas supply unit and the heater, so that the insulating film can be formed continuously for a plurality of semiconductor wafers.
[9] An insulating film forming method characterized in that a semiconductor wafer is placed on the tray of the insulating film forming apparatus according to [7] or [8] with its back surface side facing upward, and then the semiconductor wafer is placed between the source gas supply unit and the heater, and then the source gas of the insulating film is supplied from the source gas supply unit in a state where the semiconductor wafer has been heated to a predetermined temperature by the heater, so that an insulating film is formed on the back surface of the semiconductor wafer.
[10] The method of forming an insulating film according to [9] above, wherein the semiconductor wafer is a silicon wafer.
[11] The method of forming an insulating film according to [9] or [10], wherein the insulating film is an oxide film.
Effects of the invention
According to the present invention, the insulating film can be formed on the back surface of the semiconductor wafer while suppressing the formation of the insulating film on the outer peripheral portion of the semiconductor wafer.
Drawings
Fig. 1 is a view showing an example of the tray for an insulating film forming apparatus according to the present invention in accordance with embodiment 1, wherein (a) is a plan view, (b) is a cross-sectional view of (a) in A-A direction, and (C) is an enlarged view of a region C surrounded by a one-dot chain line in (b).
Fig. 2 is a view showing an example of embodiment 2 of a tray for an insulating film formation apparatus according to the present invention, wherein (a) is a plan view, and (b) is a sectional view of (a) through (a).
Fig. 3 is a view showing another example of embodiment 2 of the tray for an insulating film formation apparatus according to the present invention, wherein (a) is a plan view, and (b) is a sectional view of (a) through (a).
Fig. 4 is a view showing still another example of embodiment 2 of the tray for an insulating film forming apparatus according to the present invention, wherein (a) is a cross-sectional view, and (b) and (c) are views showing a relationship between the width of the annular member and the region where the insulating film is not formed.
Fig. 5 is a view showing an appropriate example of embodiment 3 of the tray for an insulating film formation apparatus according to the present invention, wherein (a) is a plan view, (b) is a cross-sectional view A-A of (a), and (C) is an enlarged view of a region C surrounded by a one-dot chain line in (b).
Fig. 6 shows another example of the insulating film forming apparatus tray according to embodiment 3 of the present invention, in which (a) is a plan view and (B) is a B-B cross-sectional view of (a).
Fig. 7 is a view showing still another example of the insulating film forming apparatus tray according to the 3 rd aspect of the present invention, in which (a) is a view showing the annular member, and (b) is a view showing a tray in which the annular member of (a) is mounted on the tray shown in fig. 2.
Fig. 8 is a view showing an example of embodiment 1 of the insulating film formation apparatus according to the present invention.
Fig. 9 is a view showing an appropriate example of embodiment 2 of the insulating film formation apparatus according to the present invention.
Fig. 10 is a view showing an example of embodiment 3 of the insulating film formation apparatus according to the present invention.
Fig. 11 is a view showing details of the tray used in examples 1 to 4.
Fig. 12 is a diagram illustrating a positional relationship between an inner diameter of an annular groove and an outer peripheral portion of a wafer in example 1, (a) relates to a comparative example, (b) relates to invention example 2, and (c) relates to invention example 3.
Fig. 13 is a graph showing a relationship between the inner diameter of the annular groove and the thickness of the oxide film at the measurement point.
Fig. 14 is a view showing details of the tray used in invention example 5.
Fig. 15 is a diagram showing a relationship between a wafer radial position of a silicon wafer and a thickness of an oxide film.
Fig. 16 is a view showing the details of the tray used in invention example 6.
Fig. 17 is a diagram illustrating points at which the thickness of the oxide film is measured, (a) corresponds to a case where the through holes are provided every 15 °, and (b) corresponds to a case where the through holes are provided every 90 °.
Fig. 18 is a graph showing a relationship between the pitch of the through holes and the thickness of the oxide film at the measurement point.
Detailed Description
(tray for insulating film Forming apparatus)
Mode 1 >
Hereinafter, embodiments of the present invention will be described with reference to the drawings. The semiconductor wafer has a front surface as a flat surface on which devices are formed, a back surface as a flat surface on the opposite side to the front surface, and wafer end surfaces located radially outward of the front and back surfaces and connecting the outer edges of the front surface and the outer edges of the back surface. The tray for an insulating film forming apparatus according to the present invention is a tray for mounting a semiconductor wafer on an insulating film forming apparatus for forming an insulating film on a back surface of a semiconductor wafer, and includes a tray main body for mounting the semiconductor wafer. The tray main body is characterized by having a concave portion provided on an upper surface of the tray main body for accommodating the semiconductor wafer, and a circular groove provided in the concave portion, the circular groove having an inner diameter smaller than a diameter of the semiconductor wafer and an outer diameter larger than the diameter of the semiconductor wafer.
As described above, in the conventional insulating film forming apparatus, the surface on which the insulating film is formed, that is, the back surface side is placed on the tray, and the source gas is supplied from above the semiconductor wafer, so that the insulating film is formed on the back surface of the semiconductor wafer. At this time, an insulating film is formed not only on the back surface of the semiconductor wafer but also from the wafer end surface to the front surface. The insulating film formed on the wafer outer peripheral portion extending from the outer edge of the back surface to the outer edge of the wafer end surface and the front surface needs to be removed because of the nodule.
The present inventors have conducted intensive studies on a method of suppressing the formation of an insulating film on the outer peripheral portion of a semiconductor wafer as described above. In this process, focusing on a tray on which semiconductor wafers are placed, it is conceivable to provide a cylindrical recess for accommodating the semiconductor wafers on the upper surface of a tray main body as a base of the tray, and to provide an annular groove having an inner diameter smaller than the diameter of the semiconductor wafers and an outer diameter larger than the diameter of the semiconductor wafers in the recess. Further, it has been found that the formation of the insulating film on the outer peripheral portion of the semiconductor wafer can be suppressed by placing the semiconductor wafer on the tray having such a structure that the back surface side on which the insulating film is formed is upward and supplying the source gas from above the semiconductor wafer to form the insulating film. The tray for an insulating film forming apparatus according to the present invention will be described in detail below.
Fig. 1 shows an example of a tray for an insulating film forming apparatus (hereinafter, simply referred to as "tray") according to the present invention, in which (a) is a plan view, (b) is a cross-sectional view of (a) in A-A, and (C) is an enlarged view of a region C surrounded by a single-dot chain line in (b). The tray 1 for an insulating film forming apparatus shown in fig. 1 includes a tray main body 11 constituting a base of the tray 1. The upper surface 11a and the lower surface 11b of the tray main body 11 are flat. The tray body 11 has a concave portion 11c and an annular groove 11d, the concave portion 11c is provided on the upper surface 11a of the tray body 11 to accommodate the semiconductor wafer, and the annular groove 11d is provided in the concave portion 11c, has an inner diameter smaller than the diameter of the semiconductor wafer, and has an outer diameter larger than the diameter of the semiconductor wafer.
The tray main body 11 is preferably made of a material having heat resistance and deformation resistance with respect to a temperature at the time of forming the insulating film without contaminating the semiconductor wafer. For example, the tray body 11 may be constituted by an object obtained by sintering silicon carbide, or an object obtained by covering the surface of the sintered silicon carbide with a silicon carbide film.
The size of the tray main body 11 can be appropriately set in accordance with the diameter, the number of semiconductor wafers to be placed, the material constituting the tray main body 11, and the like.
The diameter of the recess 11c is equal to or larger than the outer diameter of the annular groove 11d, and can be the same as the outer diameter of the annular groove 11 d. The depth of the recess 11c is preferably equal to or greater than the thickness of the semiconductor wafer. Thus, the tray 1 (tray body 11) can hold the semiconductor wafer satisfactorily.
The annular groove 11d is provided in the recess 11c, and has an inner diameter smaller than the diameter of the semiconductor wafer and an outer diameter larger than the diameter of the semiconductor wafer. By making the inner diameter of the annular groove 11d smaller than the diameter of the semiconductor wafer, the contact area between the semiconductor wafer and the bottom of the delimited concave portion 11c can be reduced, the heat transferred from the tray main body 11 to the outer peripheral portion of the semiconductor wafer can be reduced, the temperature rise in the outer peripheral portion of the wafer can be suppressed, and the formation of the insulating film to the outer peripheral portion of the semiconductor wafer can be suppressed. Further, by making the inner diameter of the annular groove 11d larger than the diameter of the semiconductor wafer, a space can be formed below the wafer outer periphery, radiation heat from the tray main body 11 to the wafer outer periphery can be suppressed, temperature rise in the wafer outer periphery can be suppressed, and formation of the insulating film to the semiconductor wafer outer periphery can be suppressed.
Specifically, the difference between the inner diameter of the annular groove 11d and the diameter of the semiconductor wafer is preferably 10mm to 20 mm. By setting the difference between the inner diameter of the annular groove 11d and the diameter of the semiconductor wafer to 10mm or more, the heat transferred to the outer peripheral portion of the wafer can be reduced, and the effect of suppressing the formation of the insulating film on the outer peripheral portion of the wafer can be improved. Further, by setting the difference between the inner diameter of the annular groove 11d and the diameter of the semiconductor wafer to 20mm or less, the width of the region of the outer peripheral portion of the semiconductor wafer in which the formation of the insulating film is suppressed can be set to a desired value.
The difference between the outer diameter of the annular groove 11d and the diameter of the semiconductor wafer is preferably 1mm to 16 mm. By setting the difference between the outer diameter of the annular groove 11d and the diameter of the semiconductor wafer to 1mm or more, radiant heat from the tray main body 11 to the outer peripheral portion of the wafer is suppressed, and the temperature rise in the outer peripheral portion of the wafer is suppressed, so that the effect of suppressing the formation of the insulating film to the outer peripheral portion of the semiconductor wafer can be improved. The larger the difference between the outer diameter of the annular groove 11d and the diameter of the semiconductor wafer, the greater the effect of suppressing the radiant heat from the tray main body 11 to the wafer outer peripheral portion. Therefore, there is no upper limit on the difference between the outer diameter of the annular groove 11d and the diameter of the semiconductor wafer in terms of suppressing the effect of the radiant heat, but it is preferably 16mm or less in terms of the limitation of the size of the tray main body 11 or the like.
The depth of the annular groove 11d is preferably 4mm or less, which is smaller than the thickness of the tray main body 11. This can maintain the strength of the tray main body 11. The depth of the annular groove 11d is preferably 2mm or more. Thereby, the radiant heat from the tray main body 11 to the wafer outer peripheral portion is suppressed, and the temperature rise in the wafer outer peripheral portion is suppressed, so that the effect of forming the insulating film to the wafer outer peripheral portion can be improved. The depth of the annular groove 11d is a depth from the upper surface 11a of the tray main body 11.
On the tray 1 having such a structure, a semiconductor wafer is placed in the recess 11c with the back surface side of the insulating film formed upward, and the tray 1 and the semiconductor wafer are heated to a predetermined temperature by the heater, and the source gas is supplied from above the semiconductor wafer. In this way, since the inner diameter of the annular groove 11d provided in the recess 11c is smaller than the diameter of the semiconductor wafer, the contact area between the semiconductor wafer and the tray body 11 is reduced, and the heat transferred from the tray body 11 to the outer periphery of the wafer is reduced. Further, since the heat is not directly transferred from the tray main body 11 to the wafer outer peripheral portion due to the space of the annular groove 11d, the temperature rise of the wafer outer peripheral portion is suppressed. In this way, the formation of the insulating film on the outer peripheral portion of the wafer can be suppressed.
In the present invention, as shown in fig. 1 (a) to (c), it is preferable that a low heat conduction member 12 is disposed in the annular groove 11d, and the low heat conduction member 12 is made of a material having a lower heat conductivity than the material constituting the tray main body 11. This reduces the radiant heat from the tray main body 11 at the bottom of the annular groove 11d, further reduces the heat transferred to the outer peripheral portion of the wafer, and improves the effect of suppressing the formation of the insulating film on the outer peripheral portion of the wafer.
As shown in fig. 1 (d), the low heat conductive member 12 may be formed of an annular member having a size and shape fitting in the annular groove 11d, or may be formed of a plurality of block members that can be accommodated in the annular groove 11 d. The block member has any shape such as a sphere or a rectangular parallelepiped. The annular member may be disposed in the annular groove 11d as one annular member, or a plurality of annular members may be disposed in the annular groove 11d in a stacked manner. The block member may be disposed so as to be fully disposed in the annular groove 11 d. Among them, the low heat conductive member 12 is more preferably constituted by a ring-shaped member because the effect of suppressing radiant heat toward the outer peripheral portion of the wafer is obtained uniformly in the wafer circumferential direction.
The material constituting the low heat conduction member 12 is not particularly limited as long as it has a lower heat conductivity than the material constituting the tray main body 11. For example, in the case where the tray main body 11 is made of silicon carbide, the low heat conductive member 12 may be made of quartz, alumina, yttria, or the like. Among them, the low heat conductive member 12 is preferably made of quartz, because it is a material that does not contaminate the semiconductor wafer.
When the low heat conductive member 12 is formed of an annular member, the width thereof (i.e., 1/2 of the difference between the outer diameter and the inner diameter of the low heat conductive member 12) is smaller than the width of the annular groove 11d (i.e., 1/2 of the difference between the outer diameter and the inner diameter of the annular groove 11 d), and the difference is preferably 1mm or more and 2mm or less. By setting the difference between the width of the low heat conductive member 12 and the width of the annular groove 11d to 1mm or more, a sufficient gap can be formed between the low heat conductive member 12 and the annular groove 11d, and the low heat conductive member 12 can be easily placed in the annular groove 11d. Further, by setting the difference between the width of the low heat conduction member 12 and the width of the annular groove 11d to 2mm or less, the effect of suppressing radiant heat transmitted from the tray main body 11 to the semiconductor wafer can be improved.
The thickness of the low heat conductive member 12 is preferably 1mm or more and the depth of the annular groove 11d or less. By setting the thickness of the low heat conduction member 12 to 1mm or more, radiant heat transmitted from the tray main body 11 to the outer peripheral portion of the semiconductor wafer can be suppressed. Further, since the thickness of the low heat conductive member 12 is equal to or less than the depth of the annular groove 11d, the low heat conductive member 12 does not contact the semiconductor wafer, and therefore, the effect of suppressing the temperature rise in the outer peripheral portion of the semiconductor wafer can be improved. In the case where the low heat conductive member 12 is configured by stacking a plurality of annular members, the thickness means the total thickness of the plurality of annular members.
In the invention, the 2 nd mode of the tray for the insulating film forming apparatus is a tray for placing a semiconductor wafer on an insulating film forming apparatus for forming an insulating film on a back surface of the semiconductor wafer. The tray for an insulating film forming apparatus includes a tray main body on which a semiconductor wafer is placed. Here, the tray main body is characterized by having a cylindrical opening penetrating from the upper surface to the lower surface of the tray main body, and an annular support portion located at the periphery of the opening and supporting the outer periphery of the semiconductor wafer.
Fig. 2 is a view showing an example of embodiment 2 of a tray for an insulating film formation apparatus according to the present invention, wherein (a) is a plan view, and (b) is a sectional view of (a) through (a). The tray 2 for an insulating film forming apparatus shown in fig. 2 includes a tray main body 21 constituting a base of the tray. The upper surface 21a and the lower surface 21b of the tray main body 21 are flat. The tray main body 21 has a cylindrical opening 21c penetrating from the upper surface 21a to the lower surface 21b, and an annular support 21d for supporting the outer periphery of the semiconductor wafer by the upper surface 21a being located at the periphery of the opening 21 c.
When a semiconductor wafer is placed on the tray 2 having such a structure, the semiconductor wafer is placed such that the wafer back surface side on which the insulating film is formed is directed downward, and the outer peripheral portion of the semiconductor wafer is supported by the support portion 21d at the periphery of the opening 21 c. As described above, the upper surface 21a of the tray main body 21 is flat, so the upper surface of the supporting portion 21d is also flat. Therefore, the upper surface 21a of the tray main body 21 is in surface contact with the rear surface outer periphery of the semiconductor wafer.
As described above, when the tray 2 on which the semiconductor wafers are mounted is viewed from below, the back surface of the semiconductor wafer is exposed, while the wafer outer peripheral portion is covered by the support portion 21d of the tray main body 21. Therefore, when the source gas for the insulating film is supplied from below the tray 2, the source gas is supplied only to the region of the back surface of the wafer exposed by the opening 21c, and is not supplied to the outer peripheral portion of the wafer. As a result, the insulating film can be formed only on the wafer backside without forming the insulating film on the wafer periphery.
The tray main body 21 is preferably composed of a material having heat resistance and deformation resistance with respect to a temperature at the time of forming the insulating film without contaminating the semiconductor wafer. For example, the tray main body 21 may be constituted by an object obtained by sintering silicon carbide, or an object obtained by covering the surface of the sintered silicon carbide with a silicon carbide film.
The size of the tray main body 21 can be appropriately set in accordance with the diameter, the number of semiconductor wafers to be placed, the material constituting the tray main body 21, and the like.
As described above, when a semiconductor wafer is placed on the opening 21c, an area for forming an insulating film is defined on the back surface of the wafer. The diameter of the opening 21c is determined by the diameter of the semiconductor wafer to be placed and the size (width) of the outer peripheral region where the insulating film is not formed, but is preferably 2mm to 6mm smaller than the diameter of the semiconductor wafer.
Further, although only one opening 21c is provided in the tray 2 shown in fig. 2, a plurality of trays may be provided for a continuous insulating film forming apparatus for forming insulating films on the back surfaces of a plurality of semiconductor wafers.
Fig. 3 shows another example of embodiment 2 of the tray for an insulating film forming apparatus according to the present invention, wherein (a) is a plan view, and (b) is a cross-sectional view of (a) from A-A. The tray 3 for an insulating film forming apparatus shown in fig. 3 includes a tray main body 31 constituting a base of the tray 3, and both the upper surface 31a and the lower surface 31b of the tray main body 31 are flat, like the tray 2 shown in fig. 2. The tray main body 31 has a cylindrical opening 31c penetrating from the upper surface 31a to the lower surface 31 b. The opening 31c has a cylindrical 1 st portion 31e disposed on the lower surface 31b side of the tray main body 31, and a cylindrical 2 nd portion 31f disposed on the upper surface 31a side to accommodate the semiconductor wafer. The 2 nd portion 31f is defined by the side wall S and the bottom B, and the 2 nd portion 31f has the same central axis as that of the 1 st portion 31e and has a diameter larger than that of the 1 st portion 31 e. At least a part of the bottom B, which is the peripheral edge of the 1 st portion 31e, constitutes a support portion 31d.
The tray 3 having such a structure can accommodate the semiconductor wafer having the insulating film formed thereon in the 2 nd portion 31f, can hold the semiconductor wafer more favorably, and can align the semiconductor wafer more favorably.
The diameter of the 2 nd portion 31f of the tray main body 31 depends on the diameter of the semiconductor wafer accommodated, but is larger than the diameter of the semiconductor wafer, and the difference between the diameter of the 2 nd portion 31f and the diameter of the semiconductor wafer is preferably 2mm to 6 mm. This makes it possible to more favorably hold the semiconductor wafer in a state of further alignment. Further, the depth of the 2 nd portion 31f is preferably designed such that the depth of the 1 st portion 31e is 1mm or more and 2mm or less. This can hold the semiconductor wafer more favorably.
Other structures of the tray 2 can be the same as the tray 2 shown in fig. 2.
When a semiconductor wafer is placed on the tray 3 having such a structure, the semiconductor wafer is placed such that the wafer back surface side on which the insulating film is formed is housed downward in the 2 nd portion 31f, and the outer peripheral portion of the wafer is supported by the support portion 31d on the peripheral edge of the 1 st portion 31 e. Thus, the upper surface of the support portion 31d of the tray main body 31 is in surface contact with the rear surface outer periphery of the semiconductor wafer, and the wafer outer periphery is covered by the support portion 31 d.
When the source gas for the insulating film is supplied from below the tray 3 on which the semiconductor wafers are mounted in this manner, the source gas is supplied only to the region of the wafer back surface exposed by the 1 st portion 31e, and is not supplied to the wafer outer peripheral portion. As a result, the insulating film can be formed only on the wafer backside without forming the insulating film on the wafer periphery.
Fig. 4 shows still another example of embodiment 2 of the tray for an insulating film forming apparatus according to the present invention, in which (a) is a cross-sectional view, and (b) and (c) are diagrams showing a relationship between the width of the annular member and the region where the insulating film is not formed. The tray 4 shown in fig. 4 is configured such that an annular member 32 having an inner diameter smaller than the diameter of the opening 31c (i.e., the diameter of the 1 st portion 31 e) of the lower surface 31b of the tray main body 31 is disposed on the support portion 31d of the tray 3 shown in fig. 3. The upper surface 32a and the lower surface 32b of the annular member 32 are flat. In the tray 4 shown in fig. 4, the diameter of the 1 st portion 31e is smaller than the diameter of the semiconductor wafer W, but the diameter of the 1 st portion 31e may be the same as or larger than the diameter of the semiconductor wafer W as long as the inner diameter of the annular member 32 is smaller than the diameter of the semiconductor wafer W.
When the semiconductor wafer W is placed on the tray 4 having such a structure, the semiconductor wafer W is placed on the ring member 32 by being accommodated in the 2 nd portion 31f with the back surface side thereof facing downward. In this way, the upper surface 32a of the annular member 32 is in surface contact with the rear surface outer periphery of the semiconductor wafer W.
When the source gas for the insulating film is supplied from below the tray 4, the inner diameter of the annular member 32 is smaller than the diameter of the 1 st portion 31 e. Therefore, the outer peripheral portion of the wafer is covered with the annular member 32, and the source gas is supplied only to the region of the back surface of the wafer exposed by the opening 32c of the annular member 32. As a result, the insulating film can be formed only on the wafer backside without forming the insulating film on the wafer periphery.
Since the inner diameter of the annular member 32 is smaller than the diameter of the 1 st portion 31e of the tray main body 31, the size of the region where the insulating film is formed on the back surface of the semiconductor wafer W can be easily changed by changing the inner diameter of the annular member 32. Specifically, as shown in fig. 4 b, when the diameter of the opening 32c of the annular member 32 (i.e., the inner diameter of the annular member 32) is relatively large, the area where the insulating film is not formed becomes small. On the other hand, as shown in fig. 4 (c), when the diameter of the opening 32c of the annular member 32 (i.e., the inner diameter of the annular member 32) is relatively small, the area where the insulating film is not formed becomes large.
The inner diameter of the annular member 32 can be appropriately set in accordance with the region where the insulating film is formed, and is not particularly limited. On the other hand, the outer diameter of the annular member 32 is preferably 2mm or more smaller than the diameter of the 2 nd portion 31f, and is preferably 1mm or more larger than the diameter of the 1 st portion 31 e.
The annular member 32 is preferably made of a material having heat resistance and deformation resistance with respect to a temperature at the time of forming the insulating film without contaminating the semiconductor wafer W. For example, the annular member 32 may be formed of an object obtained by sintering silicon carbide, or an object obtained by covering the surface of the sintered silicon carbide with a silicon carbide film.
The tray 4 shown in fig. 4 is configured as a tray in which the annular member 32 is disposed on the support portion 31d of the tray 3 shown in fig. 3, but may be configured as a tray in which the annular member 32 is disposed on the support portion 21d of the tray 2 shown in fig. 2. In this case, if the inner diameter of the annular member 32 is smaller than the diameter of the semiconductor wafer W, the diameter of the opening 21c need not be smaller than the diameter of the semiconductor wafer W, and the diameter of the opening 21c may be the same as or larger than the diameter of the semiconductor wafer W.
Mode 3 >
In accordance with a 3 rd aspect of the tray for an insulating film forming apparatus of the present invention, a tray for placing a semiconductor wafer on an insulating film forming apparatus for forming an insulating film on a back surface of a semiconductor wafer includes a tray main body for placing a semiconductor wafer. The tray main body is characterized by having a concave portion recessed from an upper surface to a lower surface of the tray main body, being defined by a side wall and a bottom portion, for accommodating the semiconductor wafer, and being cylindrical, and a gas flow path formed as a flow path through which the inert gas flows from the lower surface to the bottom portion, the gas flow path being formed at a position where a part of the gas flow path is blocked by the semiconductor wafer when the semiconductor wafer is arranged in the concave portion in a plan view.
Fig. 5 shows an example of embodiment 3 of the tray for an insulating film forming apparatus according to the present invention, in which (a) is a plan view, (b) is a cross-sectional view of (a) and (C) is an enlarged view of a region C surrounded by a single-dot chain line in (b). The tray 5 for an insulating film forming apparatus shown in fig. 5 includes a tray main body 51 constituting a base of the tray 5. The upper surface 51a and the lower surface 51b of the tray main body 51 are flat. Further, the tray main body 51 has a cylindrical concave portion 51c recessed from the upper surface 51a toward the lower surface 51b of the tray main body 51. The recess 51c is defined by the sidewall S and the bottom B, and accommodates the semiconductor wafer. The tray main body 51 further includes a gas flow path P formed as a space penetrating from the lower surface 51B to the bottom B, and serving as a flow path for flowing the inert gas. The gas flow path P is formed at a position where a part of the gas flow path P is blocked by the semiconductor wafer when the semiconductor wafer is arranged in the recess 51c in a plan view.
The tray main body 51 is preferably composed of a material having heat resistance and deformation resistance with respect to a temperature at the time of forming the insulating film without contaminating the semiconductor wafer. For example, the tray main body 51 may be constituted by an object obtained by sintering silicon carbide, or an object obtained by covering the surface of the sintered silicon carbide with a silicon carbide film.
The size of the tray main body 51 can be appropriately set in accordance with the diameter, the number of semiconductor wafers to be placed, the material constituting the tray main body 51, and the like.
The diameter of the recess 51c is larger than the diameter of the semiconductor wafer, and the difference between the diameter of the recess 51c and the diameter of the semiconductor wafer is preferably 2mm to 6 mm. This enables the semiconductor wafer to be held well. The depth of the recess 51c is preferably equal to or greater than the thickness of the semiconductor wafer.
The gas flow path P has an annular groove 51e having an inner diameter smaller than the diameter of the semiconductor wafer and an outer diameter larger than the diameter of the semiconductor wafer on the upper surface 51a of the tray main body 51, and a plurality of through holes 51d arranged in the annular groove 51 e.
The through hole 51d is disposed in the annular groove 51e, penetrates from the lower surface 51b of the tray main body 51 to the bottom of the annular groove 51e, and constitutes a part of a flow path through which the inert gas flows. The shape of the through hole 51d is not particularly limited, and may be circular, elliptical, triangular, polygonal, or the like.
The diameter of the through hole 51d is preferably 0.5mm or more and the width of the annular groove 51e or less. Thus, the flow rate of the inert gas can be controlled to an appropriate value. In the present specification, when the shape of the through hole 51d is other than a circle, the diameter of the through hole 51d refers to the diameter of the circle inscribed in the through hole 51 d.
The annular groove 51e forms a part of a flow path through which the inert gas flows. By making the inner diameter of the annular groove 51e smaller than the diameter of the semiconductor wafer, the contact area between the semiconductor wafer and the bottom of the delimiting recess 51c can be reduced, the heat transferred to the outer peripheral portion of the wafer can be reduced, and the formation of the insulating film on the outer peripheral portion of the wafer can be suppressed. Further, since the semiconductor wafer partially covers the opening of the annular groove 51e, a part of the inert gas flowing from below collides with the rear surface outer peripheral portion of the semiconductor wafer and flows along the annular groove 51e, and the formation of the insulating film can be suppressed even in the portion without the through hole 51 d.
Further, by making the outer diameter of the annular groove 51e larger than the diameter of the semiconductor wafer, the inert gas can be favorably passed near the wafer outer periphery, and the insulating film can be suppressed from being formed on the wafer outer periphery.
The inner diameter of the annular groove 51e is larger than the diameter of the semiconductor wafer, and the difference between the inner diameter of the annular groove 51e and the diameter of the semiconductor wafer is preferably 2mm to 6 mm. This can further improve the effect of reducing the heat transferred to the outer peripheral portion of the wafer to suppress the formation of the insulating film on the outer peripheral portion of the wafer and the effect of allowing the inert gas to flow along the annular groove 51e to suppress the formation of the insulating film even in the portion where the through hole 51d is not provided.
The outer diameter of the annular groove 51e is larger than the diameter of the semiconductor wafer, and the difference between the outer diameter of the annular groove 51e and the diameter of the semiconductor wafer is preferably 2mm to 6 mm. Thus, the inert gas can be more favorably passed near the outer peripheral portion of the wafer, and the formation of the insulating film on the outer peripheral portion of the wafer can be further suppressed.
The through holes 51d are preferably arranged at an angle of 60 ° or less, more preferably at an angle of 30 ° or less, even more preferably at an angle of 15 ° or less, even more preferably at an angle of 10 ° or less, and most preferably at an angle of 5 ° or less in the circumferential direction of a circle concentric with the center of the concave portion 51 c. The through holes 51d are preferably uniformly arranged in the circumferential direction of the circle. As shown in the embodiment described below, the through holes 51d are uniformly arranged at an angle of 15 ° or less in the circumferential direction of the wafer, so that the insulating film can be substantially prevented from being formed on the outer peripheral portion of the wafer in the entire circumferential direction, and the insulating film can be prevented from being formed on the outer peripheral portion of the wafer in the entire circumferential direction by being uniformly arranged at an angle of 5 ° or less.
When forming an insulating film on a semiconductor wafer, the semiconductor wafer is placed on the tray 5, an inert gas is supplied from below the tray main body 51 to flow through the gas flow path P, and a source gas is supplied from above the semiconductor wafer. At this time, the semiconductor wafer is placed in the recess 51c with the back surface side where the insulating film is formed being housed upward. In this way, when the semiconductor wafer is placed in the recess 51c in a plan view, the gas flow path P provided in the tray main body 51 is formed at a position where a part of the gas flow path P is blocked by the semiconductor wafer, so that the inert gas flowing through the gas flow path P passes near the wafer outer periphery and the source gas of the insulating film is prevented from reaching the wafer outer periphery. In this way, the insulating film can be prevented from being formed on the outer peripheral portion of the wafer.
In the tray 5 shown in fig. 5, the gas flow path P has the annular groove 51e, but this is not necessarily required, and the gas flow path P may have only a plurality of through holes 51d. In this case, the through-hole 51d is arranged at a position where a part of the through-hole 51d is blocked by the semiconductor wafer when the semiconductor wafer is arranged in the recess 11c in a plan view.
When the gas flow path P has only a plurality of through holes 51d, the diameter of the through holes 51d is preferably a diameter that can control the flow rate of the inert gas to an appropriate value.
In addition, in the case where the gas flow path P has only the plurality of through holes 51d, the inert gas is more likely to be concentrated in the vicinity of the through holes 51d than in the case where the gas flow path P has the annular groove 51e. Therefore, from the standpoint of more uniformly supplying the inert gas to the outer peripheral portion of the wafer, the gas flow path P preferably has an annular groove 51e like the tray 5 shown in fig. 5, as compared with having only a plurality of through holes 51d.
Fig. 6 shows another example of the insulating film forming apparatus tray according to embodiment 3 of the present invention, in which (a) is a plan view and (B) is a B-B cross-sectional view of (a). The structures 61, 61a to 61c and 61e of the insulating film formation unit tray 6 shown in fig. 6 correspond to the structures 51, 51a to 51c and 51e of the insulating film formation unit tray 5 shown in fig. 5, respectively, and the description thereof is omitted.
In the insulating film forming apparatus tray 6 shown in fig. 6, the through hole 61d is formed by a long hole along a circle (annular groove 61e in fig. 6) concentric with the center of the concave portion 61 c. As shown in fig. 6, since the through holes 61d are formed of long holes, the inert gas can be uniformly supplied to the wafer outer peripheral portion, and therefore, the effect of suppressing the formation of the insulating film on the wafer outer peripheral portion can be obtained more uniformly in the wafer circumferential direction. In the example shown in fig. 6, the through holes 61d are provided every 90 ° in the circumferential direction of a circle concentric with the center of the concave portion 61c, but the present invention is not limited thereto, and may be provided every 120 °, 180 °, for example.
Fig. 7 shows another example of the insulating film forming apparatus tray according to embodiment 3 of the present invention, in which (a) is a ring member, and (b) is a tray in which the ring member of (a) is mounted on the tray shown in fig. 6. The annular member 62 shown in fig. 7 a has a plurality of through holes (2 nd through holes) 62a, and the plurality of through holes 62a are arranged uniformly (every 45 ° in the example of fig. 7) in the circumferential direction of a circle concentric with the center of the annular member 62. The inner diameter of the annular member 62 shown in fig. 7 (a) is larger than the inner diameter of the annular groove 61e of the tray 6 shown in fig. 6, and the outer diameter of the annular member 62 is smaller than the outer diameter of the annular groove 61e of the tray 6 shown in fig. 6.
Fig. 7 (b) shows a tray 7 in which the annular member 62 shown in fig. 7 (a) is disposed in the annular groove 61e of the tray 6 shown in fig. 6. The plurality of through holes 62a of the annular member 62 are arranged in the long holes, and thus the area through which the inert gas flows can be limited to the through holes 62a. Further, by replacing the annular members 62 with the annular members 62 having different numbers of through holes 62a (intervals between the through holes 62 a), the amount of the inert gas to be supplied can be adjusted, and the range in which the formation of the insulating film is suppressed can be easily adjusted.
(insulating film Forming apparatus)
Mode 1 >
The 1 st aspect of the insulating film forming apparatus according to the present invention is an apparatus for forming an insulating film on a back surface of a semiconductor wafer, comprising a source gas supply unit disposed above a tray, a heater disposed below the tray, and the tray for the insulating film forming apparatus according to the 1 st aspect of the present invention, wherein the source gas supply unit supplies a source gas of the insulating film to the back surface of the semiconductor wafer placed on the tray, and the heater heats the semiconductor wafer.
Fig. 8 shows an example of embodiment 1 of the insulating film formation apparatus according to the present invention. The insulating film forming apparatus 100 shown in fig. 8 includes a tray 1, a source gas supply unit 120, a heater 130, and a quartz plate 140.
The tray 1 is the tray 1 of the present invention shown in fig. 1, and is omitted because the detailed description thereof has been made. A carrying roller 1a is provided at a lower portion of the tray 1 so that the tray 1 can be carried.
The source gas supply unit 120 is disposed above the tray 1, and supplies source gas for the insulating film to the back surface of the semiconductor wafer W placed on the tray 1 via the recess 11c of the tray 1. In the example shown in fig. 8, silane (SiH) which is a source gas for supplying a silicon oxide film is supplied 4 ) Oxygen (O) 2 ) However, other source gases may be supplied to form other insulating films such as a nitride film.
As shown in fig. 8, the raw material gas supply unit 120 is configured to supply inert gas such as nitrogen or rare gas so as to surround the raw material gas in order to reduce the mixing of impurities into the raw material gas.
The heater 130 is disposed below the tray 1, and heats the semiconductor wafer W to a temperature at which the source gas supplied to the rear surface of the semiconductor wafer W is decomposed to form an insulating film on the rear surface of the semiconductor wafer W.
The quartz plate 140 is provided to ensure the operation route of the conveying rollers 1a of the conveying tray 1. For example, in the case where the conveying rollers 1a are provided at four corners of the back surface of the tray 1, two elongated quartz plates 140 may be arranged in parallel in the conveying direction of the tray 1, and the tray 1 may be movable on the quartz plates 140 via the conveying rollers 1 a.
Here, the operation of the insulating film formation apparatus 100 will be described. First, the semiconductor wafer W is placed on the tray 1 so that the rear surface side where the insulating film is formed is accommodated in the recess 11 c. Next, the tray 1 is disposed below the source gas supply unit 120 and above the heater 130.
Next, the semiconductor wafer W is heated to a predetermined temperature by the heater 130, and then the source gas for the insulating film is supplied from the source gas supply unit 120. In this way, the formation of the insulating film on the outer peripheral portion of the semiconductor wafer W can be suppressed, and the insulating film can be formed on the back surface of the semiconductor wafer W.
In addition, the insulating film forming apparatus 100 is preferably configured to include a plurality of trays 1, and to convey the plurality of trays 1 between the source gas supply unit 120 and the heater 130. This allows the insulating film to be formed continuously for a plurality of semiconductor wafers W.
An insulating film forming apparatus according to claim 2 of the present invention is an apparatus for forming an insulating film on a back surface of a semiconductor wafer, comprising a source gas supply unit, a heater, and the tray for an insulating film forming apparatus according to the present invention, wherein the source gas supply unit is disposed below the tray, the source gas for the insulating film is supplied to the back surface of the semiconductor wafer placed on the tray through the opening of the tray, and the heater is disposed above the tray, and the semiconductor wafer is heated.
Fig. 9 shows an appropriate example of embodiment 2 of the insulating film formation apparatus according to the present invention. The insulating film forming apparatus 200 shown in fig. 9 includes a tray 3, a source gas supply unit 120, an inert gas supply unit 150, and a heater 130.
The tray 3 is the tray 3 of the present invention shown in fig. 3, and is omitted because the detailed description thereof has been made. A carrying roller 3a is provided at a lower portion of the tray 3 so that the tray 3 can be carried.
The source gas supply unit 120 is disposed below the tray 3, and supplies source gas for the insulating film to the back surface of the semiconductor wafer W placed on the tray 3 through the opening 31c (1 st portion 31 e) of the tray 3. In the example shown in fig. 9, silane (SiH) which is a source gas for forming a silicon oxide film is supplied 4 ) Oxygen (O) 2 ) However, other source gases may be supplied to form other insulating films such as a nitride film.
As shown in fig. 9, the raw material gas supply unit 120 is configured to supply inert gas such as nitrogen or rare gas so as to surround the raw material gas in order to reduce the mixing of impurities into the raw material gas.
The heater 130 is disposed above the tray 3, and heats the semiconductor wafer W to a temperature at which the source gas supplied to the rear surface of the semiconductor wafer W is decomposed to form an insulating film on the rear surface of the semiconductor wafer W.
As shown in fig. 9, an inert gas supply unit 150 is preferably provided, and the inert gas supply unit 150 is disposed above the tray 3 and below the heater 130 to supply inert gas to the front surface of the semiconductor wafer W placed on the tray 3. Thus, when the semiconductor wafer W is pushed downward during the formation of the insulating film, the semiconductor wafer W can be prevented from floating even when the source gas is supplied to the back surface of the semiconductor wafer W by the source gas supply unit 120.
Here, the operation of the insulating film formation apparatus 200 will be described. First, the semiconductor wafer W is placed on the tray 3 such that the wafer back surface side on which the insulating film is formed is housed in the 2 nd portion 31f, the 1 st portion 31e is closed, and the wafer outer peripheral portion is supported by the support portion 31d on the peripheral edge of the 1 st portion 31 e.
Next, the tray 3 is disposed above the source gas supply unit 120 and below the inert gas supply unit 150. Next, after the semiconductor wafer W is heated to a predetermined temperature by the heater 130, an inert gas is supplied from the inert gas supply unit 150, and a source gas of the insulating film is supplied from the source gas supply unit to the back surface of the semiconductor wafer W through the opening 31c (1 st portion 31 e) of the tray 3. In this way, the insulating film can be formed on the back surface of the semiconductor wafer W without forming the insulating film on the outer peripheral portion of the semiconductor wafer W.
Further, the insulating film forming apparatus 200 preferably includes a plurality of trays 3, and the plurality of trays 3 are preferably transported between the source gas supply unit 120 and the inert gas supply unit 150. This allows the insulating film to be formed continuously for a plurality of semiconductor wafers W.
Mode 3 >
A 3 rd aspect of the insulating film forming apparatus according to the present invention is an apparatus for forming an insulating film on a back surface of a semiconductor wafer, comprising a source gas supply unit disposed above the tray, a heater disposed below the tray, heating the semiconductor wafer, an inert gas supply unit disposed below the tray and above the heater, and the inert gas supply unit supplying inert gas from a lower surface side of the tray main body to flow through a gas flow path of the tray main body.
Fig. 10 shows an example of embodiment 3 of the insulating film formation apparatus according to the present invention. The insulating film forming apparatus 300 shown in fig. 10 includes a tray 5, a source gas supply unit 120, a heater 130, and an inert gas supply unit 150.
The tray 5 is the tray 5 of the present invention shown in fig. 5, and is omitted because the detailed description thereof has been made. A carrying roller 5a is provided at a lower portion of the tray 5 so that the tray 5 can be carried.
The source gas supply unit 120 is disposed above the tray 5, and supplies source gas for the insulating film to the back surface of the semiconductor wafer W placed on the tray 5 through the recess 51c of the tray 5. In the example shown in fig. 10, silane (SiH) which is a source gas for forming a silicon oxide film is supplied 4 ) Oxygen (O) 2 ) However, other source gases may be supplied to form other insulating films such as a nitride film.
As shown in fig. 10, the raw material gas supply unit 120 is configured to supply inert gas such as nitrogen or rare gas so as to surround the raw material gas in order to reduce the mixing of impurities into the raw material gas.
The heater 130 is disposed below the tray 5, and heats the semiconductor wafer W to a temperature at which the source gas supplied to the rear surface of the semiconductor wafer W is decomposed to form an insulating film on the rear surface of the semiconductor wafer W.
The inert gas supply unit 150 is disposed below the tray 5 and above the heater 130, and supplies inert gas from the lower surface 51b side of the tray main body 51 to the gas flow path P of the tray main body 51.
Here, the operation of the insulating film formation apparatus 300 will be described. First, the semiconductor wafer W is placed on the tray 5 so that the back surface side where the insulating film is formed is accommodated in the recess 51 c. Next, the tray 5 is disposed below the source gas supply unit 120 and above the inert gas supply unit 150.
Next, after the semiconductor wafer W is heated to a predetermined temperature by the heater 130, the inert gas is flowed from the inert gas supply unit 150 to the gas flow path P of the tray main body 51, and the source gas of the insulating film is supplied from the source gas supply unit 120 to the back surface of the semiconductor wafer W. In this way, the insulating film can be formed on the back surface of the semiconductor wafer W while suppressing the formation of the insulating film on the outer peripheral portion of the semiconductor wafer W.
Further, the insulating film forming apparatus 300 preferably includes a plurality of trays 5, and the plurality of trays 5 are preferably transported between the source gas supply unit 120 and the inert gas supply unit 150. This allows the insulating film to be formed continuously for a plurality of semiconductor wafers W.
(insulating film Forming method)
Mode 1 >
In the insulating film forming method according to claim 1 of the present invention, the back surface side of the semiconductor wafer is placed on the tray according to claim 1 of the insulating film forming apparatus of the present invention, and then the semiconductor wafer is placed between the source gas supply unit and the heater, and after the semiconductor wafer has been heated to a predetermined temperature by the heater, the source gas of the insulating film is supplied from the source gas supply unit, and the insulating film is formed on the back surface of the semiconductor wafer.
In the following, an example of embodiment 1 of the insulating film formation method of the present invention will be described by taking, as an example, a case of using the insulating film formation apparatus 100 of the present invention shown in fig. 8. First, the semiconductor wafer W is placed on the tray 1 so that the rear surface side where the insulating film is formed is accommodated in the recess 11 c.
The semiconductor wafer W is not particularly limited, and may be a silicon wafer, a germanium wafer, a silicon carbide wafer, a gallium arsenide wafer, or the like. In particular, as the semiconductor wafer, a silicon wafer can be suitably used.
The diameter of the semiconductor wafer W can be set according to the material and design constituting the semiconductor wafer W, and is not particularly limited. In the case where the semiconductor wafer W is a silicon wafer, the diameter thereof may be 150mm or more, for example, 150mm, 200mm, 300mm, or 450mm.
The insulating film is not particularly limited, but may be an oxide film, a nitride film, or the like. For example, in the case of an epitaxial silicon wafer having a silicon epitaxial layer formed on a silicon wafer, the oxide film can be a silicon oxide film or a silicon nitride film.
Next, the tray 1 is disposed below the source gas supply unit 120 and above the heater 130.
Next, after the semiconductor wafer W is heated to a predetermined temperature by the heater 130, a source gas for an insulating film is supplied from the source gas supply unit 120, and an insulating film is formed on the back surface of the semiconductor wafer W.
The temperature of the semiconductor wafer at the time of forming the insulating film depends on the kind of the insulating film formed, but for example, in the case of forming a silicon oxide film on the back surface of a silicon wafer, it is preferably 380 ℃ to 460 ℃.
The source gas supplied from the source gas supply unit 120 can be an appropriate gas corresponding to the source material of the insulating film. For example, in the case where the insulating film is a silicon oxide film, siH can be used as a source gas 4 Gas and O 2 And (3) gas. In addition, in the case where the insulating film is a silicon nitride film, siH can be used as 4 Gas and N 2 Gas or ammonia (NH) 3 ) And (3) air.
The region where the insulating film is not formed can be adjusted according to the inner diameter and depth of the annular groove 11d or according to the thickness of the low heat conductive member 12.
In this way, the formation of the insulating film on the outer peripheral portion of the semiconductor wafer W can be suppressed, and the insulating film can be formed on the back surface of the semiconductor wafer W.
In the insulating film forming method according to claim 2 of the present invention, the semiconductor wafer is placed on the tray of the insulating film forming apparatus according to claim 2, and then the semiconductor wafer is placed between the source gas supply unit and the heater, and then the source gas of the insulating film is supplied from the source gas supply unit in a state where the semiconductor wafer has been heated to a predetermined temperature by the heater, so that the insulating film is formed on the back surface of the semiconductor wafer.
In the following, an example of embodiment 2 of the insulating film formation method of the present invention will be described by taking as an example a case where an appropriate insulating film formation apparatus 200 of the present invention shown in fig. 9 is used. First, the semiconductor wafer W is placed on the tray 3 such that the wafer back surface side on which the insulating film is formed is housed in the 2 nd portion 31f, the 1 st portion 31e is closed, and the wafer outer peripheral portion is supported by the support portion 31d on the peripheral edge of the 1 st portion 31 e.
The semiconductor wafer W is not particularly limited, and may be a silicon wafer, a germanium wafer, a silicon carbide wafer, a gallium arsenide wafer, or the like. In particular, as the semiconductor wafer, a silicon wafer can be suitably used.
The insulating film is not particularly limited, but may be an oxide film, a nitride film, or the like. For example, in the case of an epitaxial silicon wafer having a silicon epitaxial layer formed on a silicon wafer, the oxide film can be a silicon oxide film or a silicon nitride film.
Next, the tray 3 is disposed above the source gas supply unit 120 and below the inert gas supply unit 150.
Next, after the semiconductor wafer W is heated to a predetermined temperature by the heater 130, an inert gas is supplied from the inert gas supply unit 150, and a source gas for the insulating film is supplied from the source gas supply unit 120 to the back surface of the semiconductor wafer W through the opening 31c (1 st portion 31 e) of the tray 3. The temperature of the semiconductor wafer W at the time of forming the insulating film depends on the kind of insulating film formed, but for example, in the case of forming a silicon oxide film on the back surface of a silicon wafer, it is preferably 380 ℃ to 460 ℃.
The source gas supplied from the source gas supply unit 120 can be an appropriate gas corresponding to the source material of the insulating film. For example, in the case where the insulating film is a silicon oxide film, siH can be used as a source gas 4 Gas and O 2 And (3) gas. In addition, in the case where the insulating film is a silicon nitride film, siH can be used as 4 Gas and N 2 Gas or ammonia (NH) 3 ) And (3) air.
As the inert gas supplied from the inert gas supply unit 150, N can be used 2 Gases, noble gases, and the like.
In this way, the insulating film can be formed on the back surface of the semiconductor wafer W without forming the insulating film on the outer peripheral portion of the semiconductor wafer W.
Mode 3 >
In the insulating film forming method according to claim 3 of the present invention, the semiconductor wafer is placed with the back surface side thereof facing upward on the tray according to claim 3 of the insulating film forming apparatus of the present invention, and then, after the semiconductor wafer is placed between the source gas supply unit and the inert gas supply unit, the inert gas is supplied from the inert gas supply unit in a state where the semiconductor wafer has been heated to a predetermined temperature by the heater, and the inert gas is circulated to the gas flow path of the tray main body, and the source gas of the insulating film is supplied from the source gas supply unit to the back surface of the semiconductor wafer, thereby forming the insulating film on the back surface of the semiconductor wafer.
An example of the insulating film formation method according to the present invention will be described below by taking as an example a case where an appropriate insulating film formation apparatus 300 according to the present invention shown in fig. 10 is used. First, the semiconductor wafer W is placed on the tray 5 so that the back surface side where the insulating film is formed is accommodated in the recess 51 c.
The semiconductor wafer W is not particularly limited, and may be a silicon wafer, a germanium wafer, a silicon carbide wafer, a gallium arsenide wafer, or the like. In particular, as the semiconductor wafer, a silicon wafer can be suitably used.
The diameter of the semiconductor wafer W can be set according to the material and design constituting the semiconductor wafer W, and is not particularly limited. In the case where the semiconductor wafer W is a silicon wafer, the diameter thereof may be 150mm or more, for example, 150mm, 200mm, 300mm, or 450mm.
The insulating film is not particularly limited, but may be an oxide film, a nitride film, or the like. For example, in the case of an epitaxial silicon wafer having a silicon epitaxial layer formed on a silicon wafer, the oxide film can be a silicon oxide film or a silicon nitride film.
Next, the tray 5 is disposed above the source gas supply unit 120 and below the inert gas supply unit 150.
Next, after the semiconductor wafer W is heated to a predetermined temperature by the heater 130, an inert gas is supplied from the inert gas supply unit 150, the inert gas is circulated to the gas flow path P of the tray main body 51, and a source gas for an insulating film is supplied from the source gas supply unit 120, so that an insulating film is formed on the back surface of the semiconductor wafer W.
The temperature of the semiconductor wafer W at the time of forming the insulating film depends on the kind of insulating film formed, but for example, in the case of forming a silicon oxide film on the back surface of a silicon wafer, it is preferably 380 ℃ to 460 ℃.
The source gas supplied from the source gas supply unit 120 can be an appropriate gas corresponding to the source material of the insulating film. For example, in the case where the insulating film is a silicon oxide film, siH can be used as a source gas 4 Gas and O 2 And (3) gas. In addition, in the case where the insulating film is a silicon nitride film, siH can be used as 4 Gas and N 2 Gas or ammonia (NH) 3 ) And (3) air.
As the inert gas supplied from the inert gas supply unit 150, N can be used 2 Gases, noble gases, and the like.
The region where the insulating film is not formed can be adjusted according to the flow rate of the inert gas supplied from the inert gas supply unit 150, the diameter of the through hole 51d, and the inner diameter of the annular groove 51 e.
In this way, the insulating film can be prevented from being formed on the outer periphery of the semiconductor wafer W, and the insulating film can be formed on the back surface of the semiconductor wafer W.
Example 1
Hereinafter, examples of the present invention will be described, but the present invention is not limited to the examples.
(inventive example 1)
A silicon oxide film was formed on the back surface of a silicon wafer using the insulating film forming apparatus 100 shown in fig. 8 including the tray 1 shown in fig. 1. Fig. 11 (a) to (c) show details of the dimensions of the tray 1. As shown in fig. 11 (d), the annular groove 11d provided in the upper surface 11a of the tray main body 11 has an inner diameter of 195mm, an outer diameter of 216mm, and a width of 10.5mm. Further, the low heat conductive member 12 is constituted by a quartz ring (width: 9.5mm, thickness: 2 mm).
Specifically, first, a silicon wafer having a diameter of 200mm is prepared, and the silicon wafer is placed on the tray 1 so as to be accommodated in the recess 11c with the back surface side of the insulating film formed upward.
Next, the tray 1 is disposed below the source gas supply unit 120 of the insulating film formation apparatus 100 and above the heater 130.
Then, the silicon wafer is heated to 450 ℃ by the heater 130 and kept from the original stateThe material gas supply unit 120 supplies SiH 4 Gas and O 2 And (3) gas. Thus, a silicon oxide film is formed on the back surface of the silicon wafer.
(inventive example 2)
In the same manner as in inventive example 1, a silicon oxide film was formed on the back surface of a silicon wafer having a diameter of 200 mm. However, as the tray 1, the inner diameter of the annular groove 11d provided on the upper surface 11a of the tray main body 11 was set to 190mm, and the width of the quartz ring was set to 12mm. Other conditions were exactly the same as in inventive example 1.
Inventive example 3
In the same manner as in inventive example 1, a silicon oxide film was formed on the back surface of a silicon wafer having a diameter of 200 mm. However, as the tray 1, the inner diameter of the annular groove 11d provided on the upper surface 11a of the tray main body 11 was set to 180mm, and the width of the quartz ring was set to 17mm. Other conditions were exactly the same as in inventive example 1.
Example 4 of the invention
In the same manner as in inventive example 1, a silicon oxide film was formed on the back surface of a silicon wafer having a diameter of 200 mm. However, as the tray 1, the inner diameter of the annular groove 11d provided on the upper surface 11a of the tray main body 11 was 185mm, and the width of the quartz ring was 14.5mm. Other conditions were exactly the same as in inventive example 1.
Comparative example
In the same manner as in inventive example 1, a silicon oxide film was formed on the back surface of a silicon wafer having a diameter of 200 mm. However, as the tray 1, the inner diameter of the annular groove 11d provided on the upper surface 11a of the tray main body 11 was set to 200mm, and the width of the quartz ring was set to 7mm. Other conditions were exactly the same as in inventive example 1.
(conventional example 1)
A silicon oxide film was formed on the back surface of the silicon wafer in the same manner as in inventive example 1. However, the formation of the silicon oxide film is performed using the apparatus described in patent document 1. Other conditions were exactly the same as in inventive example 1.
< evaluation of oxide film thickness >
The thicknesses of the oxide films formed on the silicon wafers of examples 1 to 4, comparative example and conventional example 1 were measured. The thicknesses of the silicon wafers of examples 1 to 4 and comparative examples were measured by a film thickness measuring apparatus (Nanometric Co., ltd., nanospec 8000 XSE) at a position 99.5mm from the center of the recess. Fig. 12 is a diagram illustrating a positional relationship between an inner diameter of the annular groove and an outer peripheral portion of the wafer, (a) relates to a comparative example, (b) relates to invention example 2, and (c) relates to invention example 3. On the other hand, regarding the silicon wafer of conventional example 1, the thickness of the oxide film was measured every 90 °, and the average value thereof was obtained. The measurement results obtained are shown in fig. 13.
As is clear from fig. 13, the average value of the thickness of the oxide film was about 3500 Å in the conventional example 1. In a comparative example in which the inner diameter of the annular groove provided on the upper surface of the tray main body is equal to the diameter of the silicon wafer, the thickness of the oxide film is the same as in the conventional example. On the other hand, in the invention examples 1 to 4, the thickness of the oxide film was decreased as compared with the conventional example 1, and the thickness of the oxide film was decreased as the inner diameter of the annular groove was decreased. In particular, in invention examples 3 and 4 in which the inner diameter of the annular groove was 185mm or less, the thickness of the oxide film was significantly reduced, and in invention example 4, the thickness of the oxide film was zero.
Example 2
Example 5 of the invention
Using the insulating film forming apparatus 200 shown in fig. 9 including the tray 3 shown in fig. 3, a silicon oxide film was formed only on the back surface of the silicon wafer. Fig. 14 (a) and (b) show details of the dimensions of the tray 3.
Specifically, first, a silicon wafer having a diameter of 200mm is prepared, and the wafer is placed such that the back surface side of the wafer on which the insulating film is formed is housed downward in the 2 nd portion 31f, the 1 st portion 31e is closed, and the peripheral portion of the wafer is supported by the support portion 31d on the peripheral edge of the 1 st portion 31 e.
Next, the tray 3 is disposed above the source gas supply unit 120 and below the inactive gas supply unit 150 of the insulating film formation apparatus 200.
Then, the silicon wafer is heated to 450 ℃ by the heater 130 and held, and N is supplied from the inert gas supply unit 150 2 Gas, and SiH is supplied from the source gas supply unit 150 2 Gas and O 2 And (3) gas. Thus, a silicon oxide film was formed only in a region 196mm from the center diameter on the back surface of the silicon wafer.
(conventional example 2)
A silicon oxide film was formed on the back surface of the silicon wafer in the same manner as in inventive example 5. However, the formation of the silicon oxide film is performed using the apparatus described in patent document 1, and as a result, a silicon oxide film is formed on the back surface and the outer periphery of the silicon wafer.
< evaluation of oxide film thickness >
Regarding the silicon wafers of the inventive examples and the conventional examples, the thickness of the oxide film formed was measured. Specifically, the thickness of the oxide film was measured by a film thickness measuring device (Nanospec 8000XSE, manufactured by nanomerics corporation) at the center of the back surface of the wafer, at a position 50mm from the center of the back surface in the wafer radial direction, and at a position 99mm from the center of the back surface in the wafer radial direction, as shown in fig. 14 (c). The measurement results obtained are shown in fig. 15.
As is clear from fig. 15, in conventional example 2, an oxide film having a thickness of about 3500 Å is formed over the entire silicon wafer. On the other hand, in invention example 5, it was found that the oxide film thickness was zero at a position 99mm from the center, and the oxide film could be formed only on the back surface of the wafer without forming the oxide film on the outer peripheral portion of the wafer.
Example 3
(inventive example 6)
A silicon oxide film was formed on the back surface of a silicon wafer using the insulating film forming apparatus 300 shown in fig. 10 having the tray 5 shown in fig. 5. The through holes 51d are provided in the annular groove 51e at positions 102.5mm from the center of the recess 51c, and circular holes having diameters of 2mm are equally provided every 15 ° (i.e., 24) in the circumferential direction. Fig. 16 (a) to (c) show details of the dimensions of the tray 5.
Specifically, first, a silicon wafer having a diameter of 200mm and a thickness of 700 μm is prepared, and the silicon wafer is placed on the tray 5 so as to be accommodated in the recess 51c with the back surface side of the insulating film formed thereon.
Next, the tray 5 is disposed below the source gas supply unit 120 of the insulating film formation apparatus 300 and above the inactive gas supply unit 150.
Then, the silicon wafer is heated to 450 ℃ by the heater 130 and kept inactiveThe gas supply unit 150 supplies N 2 A gas is supplied to the gas flow path P, and SiH is supplied from the source gas supply unit 150 2 Gas and O 2 And (3) gas. Thus, a silicon oxide film is formed on the back surface of the silicon wafer.
Inventive example 7
In the same manner as in inventive example 6, a silicon oxide film was formed on the back surface of a silicon wafer having a diameter of 200 mm. However, as the tray 5, trays in which the through holes 51d are uniformly formed every 10 ° (i.e., 36) are used. Other conditions were exactly the same as in inventive example 6.
Example 8 of the invention
In the same manner as in inventive example 6, a silicon oxide film was formed on the back surface of a silicon wafer having a diameter of 200 mm. However, as the tray 5, trays in which the through holes 51d are formed uniformly every 5 ° (i.e., 72) are used. Other conditions were exactly the same as in inventive example 6.
(inventive example 9)
In the same manner as in inventive example 6, a silicon oxide film was formed on the back surface of a silicon wafer having a diameter of 200 mm. However, as the tray 5, trays in which the through holes 51d are uniformly formed every 30 ° (i.e., 12) are used. Other conditions were exactly the same as in inventive example 6.
(inventive example 10)
In the same manner as in inventive example 6, a silicon oxide film was formed on the back surface of a silicon wafer having a diameter of 200 mm. However, as the tray 5, trays in which the through holes 51d are uniformly formed every 60 ° (i.e., 6) are used. Other conditions were exactly the same as in inventive example 6.
Inventive example 11
In the same manner as in inventive example 6, a silicon oxide film was formed on the back surface of a silicon wafer having a diameter of 200 mm. However, as the tray 5, trays in which the through holes 51d are uniformly formed every 90 ° (i.e., 4) are used. Other conditions were exactly the same as in inventive example 6.
(conventional example 3)
A silicon oxide film was formed on the back surface of the silicon wafer in the same manner as in inventive example 6. However, the formation of the silicon oxide film is performed using the apparatus described in patent document 1. Other conditions were exactly the same as in inventive example 6.
< evaluation of oxide film thickness >
Regarding the silicon wafers of examples 6 to 11 and the conventional examples, the thickness of the oxide film formed was measured. The thicknesses of invention examples 6 to 11 were measured by a film thickness measuring device (Nanometric, nanospec 8000 XSE) at a position 99.5mm from the center of the recess and at an angle intermediate between adjacent through holes. For example, in invention example 6 in which through holes are provided every 15 °, the thickness of the oxide film is measured at the measurement point shown in fig. 17 (a). In invention example 11 in which the through holes were provided every 90 °, the thickness of the oxide film was measured at the measurement point shown in fig. 17 (b). On the other hand, regarding the silicon wafer of conventional example 3, the thickness of the oxide film was measured every 90 °, and the average value thereof was obtained. The measurement results obtained are shown in fig. 18.
As is clear from fig. 18, the average value of the thickness of the oxide film was about 3500 Å in the conventional example 3. On the other hand, in the invention examples 6 to 11, the thickness of the oxide film was decreased as the number of through holes was increased. In particular, in invention examples 6 to 8 in which the through holes were formed every 15 ° or less, the thickness of the insulating film was substantially zero, and in invention example 8, the thickness of the insulating film was substantially zero in the entire circumferential direction of the wafer outer peripheral portion.
Industrial applicability
According to the present invention, the formation of the insulating film on the outer peripheral portion of the semiconductor wafer can be suppressed, and the insulating film can be formed on the back surface of the semiconductor wafer, so that the present invention is useful in the semiconductor wafer manufacturing industry.
Description of the reference numerals
1,2,3,4,5,6,7 tray
1a,3a,5a carrying roller
11 Tray body 21, 31, 51, 61
11a,21a,31a,51a,61a upper surface
11b,21b,31b,51b,61b lower surface
11c,51c,61c recesses
11d annular groove
12. Low heat conduction member
12a opening part
21c,31c opening portions
21d,31d support
31e part 1
31f part 2
32 62 ring-shaped member
32a upper surface of the annular member
32b lower surface of the annular member
Opening of 32c ring-shaped member
51d,61d,62a through holes
51e,61e annular grooves
100 200, 300 insulating film forming apparatus
120. Raw material gas supply unit
130. Heater
140. Quartz plate
150. Inactive gas supply unit
B bottom part
S side wall
P gas flow path
W semiconductor wafer.
Claims (11)
1. A tray for an insulating film forming apparatus, which is a tray for placing a semiconductor wafer on an insulating film forming apparatus for forming an insulating film on a back surface of the semiconductor wafer, characterized in that,
comprises a tray main body for placing a semiconductor wafer,
the tray body has a concave portion and an annular groove,
the concave part is arranged on the upper surface of the tray main body, accommodates the semiconductor wafer, is cylindrical,
the annular groove is provided in the recess, has an inner diameter smaller than the diameter of the semiconductor wafer, and has an outer diameter larger than the diameter of the semiconductor wafer.
2. The tray for an insulating film formation apparatus according to claim 1,
the tray main body is provided with a low heat conduction member in the annular groove, and the low heat conduction member is made of a material having a lower heat conductivity than a material constituting the tray main body.
3. The tray for an insulating film formation apparatus according to claim 1 or 2,
The low heat conduction member is constituted by a ring-shaped member or a plurality of block-shaped members.
4. The tray for an insulating film formation apparatus according to claim 1 or 2,
the tray body is made of silicon carbide, and the low heat conduction member is made of quartz.
5. The tray for an insulating film formation apparatus according to claim 1 or 2,
the difference between the inner diameter of the annular groove and the diameter of the semiconductor wafer is 10mm to 20mm, and the difference between the outer diameter of the annular groove and the diameter of the semiconductor wafer is 1mm to 16 mm.
6. A tray for an insulating film formation apparatus according to claim 3,
the annular member has a width smaller than the width of the annular groove, and a difference between the width of the annular member and the width of the annular groove is 1mm to 2 mm.
7. An insulating film forming apparatus for forming an insulating film on a back surface of a semiconductor wafer, characterized in that,
a pallet comprising a raw material gas supply unit, a heater and any one of claims 1 to 6,
the source gas supply unit is disposed above the tray and supplies the source gas of the insulating film to the back surface of the semiconductor wafer placed on the tray,
The heater is disposed below the tray to heat the semiconductor wafer.
8. The apparatus for forming an insulating film according to claim 7,
comprises a plurality of trays, a carrying roller is arranged at the lower part of the tray main body,
the plurality of trays are transported between the source gas supply unit and the heater, and the insulating film can be formed continuously for a plurality of semiconductor wafers.
9. A method for forming an insulating film, characterized in that,
in the insulating film forming apparatus according to claim 7 or 8, a semiconductor wafer is placed on the tray with its back surface side facing upward, and then the semiconductor wafer is placed between the source gas supply unit and the heater, and then the source gas of the insulating film is supplied from the source gas supply unit in a state where the semiconductor wafer has been heated to a predetermined temperature by the heater, so that an insulating film is formed on the back surface of the semiconductor wafer.
10. The method for forming an insulating film according to claim 9, wherein,
the semiconductor wafer is a silicon wafer.
11. The method for forming an insulating film according to claim 9 or 10, wherein,
The insulating film is an oxide film.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2021-212944 | 2021-12-27 | ||
| JP2021212944A JP2023096901A (en) | 2021-12-27 | 2021-12-27 | Tray for insulating film forming apparatus, insulating film forming apparatus, and method for forming insulating film |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116364640A true CN116364640A (en) | 2023-06-30 |
Family
ID=86915227
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211508009.4A Pending CN116364640A (en) | 2021-12-27 | 2022-11-29 | Tray for insulating film forming apparatus, and insulating film forming method |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP2023096901A (en) |
| CN (1) | CN116364640A (en) |
-
2021
- 2021-12-27 JP JP2021212944A patent/JP2023096901A/en active Pending
-
2022
- 2022-11-29 CN CN202211508009.4A patent/CN116364640A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| JP2023096901A (en) | 2023-07-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP1348230B1 (en) | Susceptor pocket profile to improve process performance | |
| US6474987B1 (en) | Wafer holder | |
| JP3341619B2 (en) | Film forming equipment | |
| US8999063B2 (en) | Susceptor, semiconductor manufacturing apparatus, and semiconductor manufacturing method | |
| TWI424475B (en) | Film forming apparatus and film forming method | |
| KR20160146581A (en) | Reactor system for sublimation of pre-clean byproducts and method thereof | |
| US20090014127A1 (en) | Systems for plasma enhanced chemical vapor deposition and bevel edge etching | |
| US8847124B2 (en) | Heating device having a meander-shaped heating element with an insulating body accomodating the same, and the substrate processing apparatus including the same | |
| CN108475610B (en) | Uniform wafer temperature achievement in asymmetric chamber environments | |
| JP2005123532A (en) | Deposition system and deposition method | |
| KR100975717B1 (en) | Vapor phase growing apparatus and vapor phase growing method | |
| JP2009239289A (en) | Substrate support, substrate processing apparatus and method of manufacturing semiconductor device | |
| CN107004582B (en) | Film forming apparatus | |
| US20050229853A1 (en) | Multideposition SACVD reactor | |
| EP1396879B1 (en) | Method of fabricating semiconductor wafer | |
| CN116364640A (en) | Tray for insulating film forming apparatus, and insulating film forming method | |
| EP1256973A1 (en) | Heating system and method for heating an atmospheric reactor | |
| CN110629199A (en) | Method for manufacturing epitaxial silicon wafer | |
| CN115704109A (en) | SiC epitaxial wafer and method for producing SiC epitaxial wafer | |
| JP2023096893A (en) | Tray for insulating film forming apparatus, insulating film forming apparatus, and method for forming insulating film | |
| US11133207B2 (en) | Method for forming films on wafers separated by different distances | |
| US20100055330A1 (en) | Epitaxy Processing System and Its Processing Method | |
| JP2023096896A (en) | Tray for insulating film forming apparatus, insulating film forming apparatus, and method for forming insulating film | |
| US20210066113A1 (en) | Susceptor, cvd apparatus, and method for manufacturing epitaxial wafer | |
| US20230094053A1 (en) | Substrate processing method and substrate processing system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |