JP3871369B2 - Semiconductor wafer processing jig - Google Patents

Description

図５乃至図１０の写真及び表１の結果より次のことが認められる。
（１）の場合において、切削したままの支持部材１の切削表層部には、微細なクラックが無数に存在し、垂直方向に約５０μｍを超えるクラックが無数存在することが認められる。
【００４２】
また、（２）の場合において、従来の焼き鈍し処理した支持部材１の切削表層部においては、（１）の場合の未処理のものに比べて、数ミクロンの微細クラックの表面先端が丸くなっているが、垂直方向のクラックは、同様に表面部分は丸みを帯びているものの、内部には、鋭利な先端部や最深部で分岐部を有して５０μｍ以上のものも存在することが認められる。
【００４３】
本実施形態例の（３）の場合において、支持部材１の切削表層部においては微細なクラックが消失し表面は極めて平坦化され、同時に垂直方向に５０μｍを超えるクラックも無くなり、全体が丸く曲面形状となっており、また、深部方向にも鋭利な先端部は無く、ほぼＶ字状に窪んだ凹部となっていることが認められる。
【００４４】
表１において、（１）の場合には砥石跡が残り白っぽい外観を呈していた。ここで、白っぽいという外観は、塵等を放出しやすい傾向を反映する。（２）の場合には、（１）に比べて透明性が認められるが、周面に比べて白っぽい外観が認められた。本実施態様例に相当する（３）の場合には、周面とほぼ同様に透明性が認められた。
【００４５】
次に、ＬＰＣＶＤ装置を用いて本実施形態例と比較例とを比較した結果について説明する。
【００４６】
図２あるいは図１０に示すＬＰＣＶＤ装置を用いて、ウエーハ支持装置２０には、前述のように、支持部材１及び上下端板により構成されるウエーハ装置部２１に配設した。
【００４７】
また、支持部材１としては、石英ガラス円柱体に切削支持部１ａを上述の各場合（１）、（２）、（３）に切削形成した支持部材１をそれぞれ用いた。このような支持部材１を用いて構成されたＬＰＣＶＤ装置を使用して、成膜温度６５０℃、成膜圧力０．２Ｔｏｒｒ（＝２６．７Ｐａ）の条件下でモノシランガスを熱分解させ、形成されるポリシリコン膜を支持部材１の切削支持部１ａに載置した１５０ｍｍφの半導体ウエーハ２３上に５μｍ堆積させた。
【００４８】
各支持部材を用いて処理した後、それぞれのウエーハ載置部２１を取り出し、半導体ウエーハ上のパーテイクル量をレーザー散乱法によるパーテイクルカウンターにて測定し、汚染量をその数で評価した。
【００４９】
また、各支持部材１の切削支持部１ａ上に形成されたポリシリコン膜の耐剥離性を評価した。耐剥離性評価は、室温で３０分保持後６００℃まで昇温し再び室温まで冷却する事で１サイクルとする熱サイクル試験を反復繰り返して行うことにより実施した。この熱サイクルを５サイクル繰り返す毎に光学顕微鏡にて各切削支持部１ａ表面を確認しながら行い、被膜の剥離の発生が確認された熱サイクル回数で耐剥離性を示した。
【００５０】
また、各ウエーハ支持部２１を構成する他の各支持部材を用い、フッ酸と硝酸の混合溶液を用いて、ポリシリコン膜を洗浄除去して洗浄性及び耐浸食性を評価した。洗浄性及び耐浸食性の評価はＳＥＭにより測定した。これら結果を表２に示す。
【００５１】
【表２】

本実施形態例の（３）の場合では、半導体ウエーハを各支持部材１に載置してポリシリコン膜を被覆形成するに際し、支持部材１の表面は微細クラックが残存せず滑らかで、ＳＥＭ観察断面では実質的に内部進行性のクラックが残存することなく、底部から鋭角でなく緩やかな曲面で上方に広がる浅いＶ字状凹部を有するように先端径が細いバーナーを用い、切削支持部の表層面の全域がまんべんなく加熱処理されている。この（３）の場合には、切削支持部を何ら処理しない未処理の支持部材を用いた（１）の場合や、従来のガス焼成の焼き鈍し処理した支持部材を用いた（２）の場合に比べて、半導体ウエーハを汚染するパーテイクルの発生が激減することが認められ、また、耐剥離性が大幅に向上することが認められる。また、（３）の場合には、酸洗浄により被膜の除去性が高く切削支持部に後々に飛散するおそれのある被膜片が残留することがなく、さらに、フッ酸等の強酸による浸食の程度も顕著に低下することが認められる。
【００５２】
以上、説明したように、本実施形態例の構成によれば、半導体ウェーハ２３を載置支持するために石英ガラス棒を切削したウエーハ載置用溝１ａの表層面を所定に加熱処理したので、表層面には開口縁が滑らかな曲面からなる凹部が散在され、被膜の付着力を向上させると同時に酸洗浄の際には被膜片が残留することなく容易に除去されるようにすることができる。この結果、半導体ウエーハ処理工程では半導体ウエーハを汚染するパーテイクルの発生を著しく抑制することができ、また酸洗浄において浸食の程度を著しく低下させ、部材上に形成された被膜の除去を容易化することができる。
【００５３】
【発明の効果】
以上説明したように本発明の構成によれば、切削支持部の表層面には開口縁が滑らかな曲面からなる凹部が散在されているので、塵埃の汚染を十分に防止でき、長期間安定して使用可能な半導体ウエーハ処理用治具を提供することができる。
【図面の簡単な説明】
【図１】本発明の半導体ウエーハ処理用治具を示す正面説明図。
【図２】本発明の実施例で用いた縦型ＬＰＣＶＤ装置の構成を概略的に示す説明図。
【図３】支持部材の切削支持部の概略構成を示す断面図。
【図４】支持部材の切削支持部（ウエーハ載置用溝）の表層部の観察するための試料の作成手順を示す断面図（ａ），（ｂ）と、観察試料を示す斜視図（ｃ）。
【図５】本発明の実施形態例の石英ガラス製支持部材の切削支持部の図４（ｃ）における表面部１ｄの微細組織の倍率２５０倍（ａ）、及び３０００倍（ｂ）の走査型電子顕微鏡写真。
【図６】本発明の実施形態例の石英ガラス製支持部材の切削支持部の図４（ｃ）における断面図１ｅの微細組織の倍率２５０倍（ａ）及び３０００倍（ｂ）の走査型電子顕微鏡写真。
【図７】従来の石英ガラス製支持部材の切削支持部の表面部の微細組織の倍率２５０倍（ａ）及び３０００倍（ｂ）の走査型電子顕微鏡写真。
【図８】従来の石英ガラス製支持部材の切削支持部の断面部の微細組織の倍率２５０倍（ａ）及び３０００倍（ｂ）の走査型電子顕微鏡写真。
【図９】石英ガラス製支持部の切削支持部の未処理表面部の微細組織の倍率２５０倍（ａ）及び３０００倍（ｂ）の走査型電子顕微鏡写真。
【図１０】石英ガラス製支持部材の切削支持部の未処理表面の断面部の微細組織の倍率２５０倍（ａ）及び３０００倍（ｂ）の走査型電子顕微鏡写真。
【図１１】一般の縦型ＬＰＣＶＤ装置の構成を概略的に示す説明図。
【符号の説明】
１ ウエーハ支持部
１ａ 切削支持部（ウエーハ載置用溝）
１ｃ 凸部
１ｂ 切削溝
１ｄ 表面部
１ｅ 断面部
２ 連結部材
１０ 反応管
１１ 反応外管
１２ 反応内管
１３ マニホールド
１４ ガスの導入管
１５ ガスの排出管
１６ 真空ポンプ
１７ 抵抗加熱ヒータ
１８ キャッピングラフンジ
２０ ウエーハ支持装置
２１ ウエーハ載置部
２２ 保温筒
２３ 半導体ウエーハ
２４ ウエーハ支持装置回転機構[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a semiconductor wafer processing jig, and more particularly to a semiconductor wafer processing jig which is used in processing a semiconductor wafer and reduces contamination of the semiconductor wafer by reducing the generation of dust in the semiconductor manufacturing process.
[0002]
[Prior art]
In a semiconductor manufacturing process, a semiconductor wafer is processed in various processes such as heat treatment and LPCVD (Low Pressure Vapor Deposition), and the processed wafer is generally held in a predetermined support member in each process. It is processed in the reaction tube of the apparatus.
[0003]
For example, FIG. 11 is a cross-sectional explanatory view schematically showing a general configuration of vertical LPCVD. In FIG. 11, a reaction tube 10 made of quartz glass has a double structure of an outer reaction outer tube 11 and an inner reaction tube 12, and is fixed to a manifold 13 made of SUS (stainless steel). The manifold 13 is formed with a gas introduction pipe 14 and a discharge pipe 15 necessary for the reaction process. Outside the reaction tube 10, a vacuum pump 16 for gas exhaust and a resistance heater 17 for heating the inside of the reaction tube are arranged.
[0004]
The wafer mounting portion 21 on which the semiconductor wafer 23 is mounted is generally provided with a support member 30 for mounting the wafer, and the support member 30 is formed by cutting a long quartz glass body. A wafer mounting groove is provided.
[0005]
These wafer mounting grooves are usually formed by cutting with a grinder or the like, and the surface layer of the grooves is roughened by cutting so that dust or the like is likely to adhere to them. It is scattered by some external factor and contaminates the wafer. At the same time, since the wafer is scraped by the wafer when the wafer is placed, the scattering of dust and the like increases and the wafer is significantly contaminated.
[0006]
Various proposals for preventing these problems have also been made. For example, in Japanese Patent Publication No. 62-8933, it is proposed to remelt a cutting portion made of a crystalline quartz sintered body to form a quartz glass layer having a predetermined thickness, and to make the surface dense and smooth. ing. Japanese Patent Application Laid-Open No. 3-209722 proposes that the entire surface of a quartz glass member having a cut portion is periodically annealed by a burner to smooth the surface.
[0007]
[Problems to be solved by the invention]
However, in the quartz glass wafer jig proposed above, the former proposal is that the center of the jig is made of a sintered material of crystalline quartz, so that the temperature at which the crystal form transforms from the α phase to the β phase is set to 573 ° C. When used at a temperature exceeding, there is a problem that the volume is suddenly changed and the jig is damaged. Further, in order to vitrify the cut portion to a predetermined thickness, for example, after the LPCVD treatment, hydrofluoric acid or the like is included. The quartz glass layer on the surface is removed by several times of washing with the acid solution, the internal crystalline quartz sintered body is exposed, and the smooth surface is substantially eliminated.
[0008]
In the latter proposal, it was also found that although contamination can be sufficiently prevented in the cleaning process, contamination of dust cannot be sufficiently prevented under various processing conditions such as LPCVD treatment and heat treatment.
[0009]
Further, in the predetermined film forming step, a film is also formed on the surface of the semiconductor wafer processing jig other than the wafer surface, for example, as in the above LPCVD apparatus. The film formed on a member such as a semiconductor wafer processing jig is preferably in an adhering state without being peeled off during the film forming process, but as a result of examination by the inventors of the present application, the reason is as follows. Although it is not clear, it has been found that the formed film is easily peeled off in the cut portion that has been subjected to a smooth treatment substantially free of uneven portions as in the prior art.
[0010]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is a semiconductor wafer processing jig that is used to mount a semiconductor wafer in various processing steps in manufacturing a semiconductor, which solves the above-described problems of the prior art, and is contaminated with dust. It is possible to provide a semiconductor wafer processing jig made of quartz glass that can be sufficiently prevented and can be used stably for a long period of time.
[0011]
[Means for Solving the Problems]
The inventors of the present invention have examined the cutting surface state of the wafer mounting groove for mounting the wafer of the quartz glass support member and the surface state after the processing by the conventional method from a microscopic viewpoint in more detail. did.
[0012]
According to this result, the surface of the wafer mounting groove has fine cracks generated during cutting, and is remelted as in the conventional method to form a quartz glass layer having a depth greater than that of the fine cracks. Apart from the case, it was found that the surface layer portion of the fine cracks was smoothed somewhat by the normal annealing process, but the cracks still remained.
[0013]
In addition, floating fine particles such as reaction products such as Si fine particles are easily taken into these remaining fine crack gaps, and these fine particles are completely washed and removed even in an etching process using an acid solution containing hydrofluoric acid. It is industrially difficult to carry out and is likely to remain after cleaning.Furthermore, these residual fine particles are caused by microscopic cracks due to changes in processing conditions, vibrations and impacts during loading / unloading of support members and wafer placement. It was also found that it scatters from the gap.
[0014]
It has also been found that, while etching using an acid solution containing hydrofluoric acid is frequently performed, erosion occurs due to hydrofluoric acid at the deepest part of the fine cracks, increasing dust contamination.
[0015]
In order to achieve the above object, the present invention provides a semiconductor wafer processing jig used for supporting a semiconductor wafer in the processing of a semiconductor wafer.
A support member for supporting a semiconductor wafer is provided, the support member has a cutting support part for placing a semiconductor wafer formed by cutting, and a surface layer of the cutting support part is planarized, Concave portions are scattered on the surface layer of the cutting support portion, and the concave portions are formed at the bottom without constricting the middle or branching the tip in SEM observation of a cross section in a plane perpendicular to the traveling direction of a grinder or the like during cutting. Ri Do approximately V-shape extending smoothly into conical in surface layer direction from, the recess has a depth of 1μm to 50 [mu] m, 2D / 3 from the upper surface portion of the depth D of the concave recess The ratio W / D with respect to the width W at the depth position is 0.2 or more, and the surface layer surface of the cutting support portion has 1 to 50 concave portions scattered per 100 μm length range. It is characterized by.
[0016]
Further, in a semiconductor wafer processing jig used for supporting a semiconductor wafer in the processing of the semiconductor wafer, the semiconductor wafer processing tool includes a support member for supporting the semiconductor wafer, and the support member mounts the cut and formed semiconductor wafer. In the SEM observation of the cross section in the plane perpendicular to the traveling direction of the grinder or the like during cutting, the middle is located in the surface of the surface of the cutting support portion. without constriction or tip branches, Ri Contact is heat treated at a gas burner to be approximately V-shape extending smoothly into conical in surface layer direction from the bottom, the depth of the recess 1μm to 50μm And the ratio W / D of the depth D of the concave portion and the width W at a depth position of 2D / 3 from the upper surface portion of the concave portion is 0.2 or more, and the cutting support portion 1 to 50 of the concave portions are scattered on the surface layer surface of 100 μm in the length range .
[0017]
Preferably, the gas injection tip of the gas burner has a diameter of approximately 0.5 mmφ. The support member is made of quartz glass.
[0018]
Further, in a semiconductor wafer processing jig used for supporting a semiconductor wafer in the processing of the semiconductor wafer, the semiconductor wafer processing tool includes a support member for supporting the semiconductor wafer, and the support member mounts the cut and formed semiconductor wafer. The surface of the cutting support is heat-treated with a gas burner so that concave portions having smooth curved edges are scattered, and the gas injection tip of the gas burner has a diameter of approximately It has 0.5 mmφ.
Further, in a semiconductor wafer processing apparatus for heat-treating a semiconductor wafer, a semiconductor wafer processing jig used for supporting the semiconductor wafer is provided, and the semiconductor wafer processing jig is a support member for supporting the semiconductor wafer. The support member has a cutting support part for placing a semiconductor wafer that has been cut and formed, and recesses are scattered on a surface layer of the cutting support part, and the recesses are grinders at the time of cutting. In the cross section in the plane perpendicular to the traveling direction, etc., heat treatment with a gas burner so as to have a substantially V-shaped cross section that gently spreads in the shape of a mortar from the bottom to the surface layer direction without constricting the middle or branching the tip. It is characterized by being.
[0019]
The present invention is configured as described above, and the surface layer portion of the cutting support portion cut and formed on the quartz glass rod for mounting the semiconductor wafer has a microscopic trace of fine cracks generated during cutting. It has as a concave part constituted by a curved surface. On the other hand, sharp fine cracks that can proceed to the inside, especially cracks that can cause the cracks to progress continuously further into the quartz glass rod-like body that constitutes the support member at the deepest part of the crack so that there is substantially no crack. Therefore, the film formed in the member shape in the film forming process is difficult to be peeled off. On the other hand, in the acid etching process, the film is easily peeled off, and fine particles as a contamination source do not remain in the fine crack gap. For this reason, the semiconductor wafer processing jig of the present invention can be used as a wafer support member in various apparatuses in the semiconductor manufacturing process, can remarkably reduce the generation of dust during long-term use, and can be subjected to an acid cleaning process. Erosion due to hydrofluoric acid or the like used in the process is small, and the semiconductor wafer to be mounted can be used for a long time without being contaminated, and is excellent in durability.
[0020]
In the present invention, the substantially V-shaped concave portion is a surface layer surface from the bottom without constricting the middle or branching the tip in SEM observation of a cross section in a plane perpendicular to the traveling direction of a grinder or the like during cutting. It is a shape that gently spreads in the shape of a mortar in the direction and has a depth (D) of 1 to 50 μm. If the depth D is less than 1 μm, the film is too smooth, and the formed film such as polysilicon formed on the member may be peeled off during the film forming process, and the mounted wafer to be processed may be contaminated. Further, when the depth exceeds 50 μm, for example, in the cleaning process of the formed film on the cut surface layer portion, the removal of the film formed in the deep portion of the concave portion is completely lost.
[0021]
Further, the ratio W / D between the depth D of the concave portion present in the surface layer portion of the cutting support portion of the present invention and the width W at a depth position of 2D / 3 from the upper surface portion of the concave portion is 0.2 or more. The shape of the concave portion is preferably not a sharp angle but relatively wide. When W / D is less than 0.2, the recess may be selectively etched in the acid cleaning, and the surface layer portion of the cutting support portion is remarkably roughened by repeating the acid cleaning for a short time. This contaminates the wafer and makes it unusable. Here, the width W is defined as a depth position of 2D / 3 from the upper surface portion of the concave portion because the size of the width W at a position deeper than the shallow depth position near the opening edge of the concave portion is the present invention. Then it is more important.
[0022]
Moreover, the said recessed part should exist 1-50 pieces per 100 micrometers of the surface layer part of a cutting support part, Preferably it exists 2-30 pieces. If the number of the recesses is less than one, the formed film may be peeled off during the processing step. On the other hand, if the number of the recesses exceeds 50, the flat surface is substantially eliminated, the contact with the wafer is increased, and the dust source due to rubbing is increased. It is because it becomes.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below in detail with reference to the drawings.
FIG. 2 is an explanatory cross-sectional view schematically showing a general configuration of vertical LPCVD. In FIG. 2, a reaction tube 10 made of quartz glass has a double structure of an outer reaction outer tube 11 and an inner reaction tube 12, and is fixed to a manifold 13 made of SUS (stainless steel). The manifold 13 is formed with a gas introduction pipe 14 and a discharge pipe 15 necessary for the reaction process. Outside the reaction tube 10, a vacuum pump 16 for gas exhaust and a resistance heater 17 for heating the inside of the reaction tube are arranged.
[0024]
A quartz glass wafer support device 20 as a semiconductor wafer processing jig is fixed on a capping flange 18 disposed so as to be in contact with the lower opening surface of the manifold 13. A wafer support device 20 as a semiconductor wafer processing jig includes a wafer mounting portion 21 made of quartz glass and a heat insulating cylinder 22 on which the wafer support portion 21 is supported, and the heat insulating cylinder 22 is fixed on the capping flange 18. It is arranged inside the reaction tube 12.
[0025]
A support member 1 for supporting a semiconductor wafer is provided in the wafer placement portion 21, and a plurality of semiconductor wafers 23 are placed in a horizontal state by the support member 1. The wafer support device rotating mechanism 24 having a rotating shaft that passes through the capping flange 18 and is connected to the heat retaining cylinder 22 is disposed below the capping flange 18.
[0026]
FIG. 1 shows a wafer mounting portion 21 in the LPCVD apparatus shown in FIG. In FIG. 1, a wafer mounting portion 21 is composed of a plurality of standing rod-shaped support members 1 made of quartz glass and upper and lower end plates 2 (upper end portions are not shown). As shown in FIG. 1, a wafer mounting groove 1 a as a wafer mounting cutting support portion is cut and formed in a long support member 1 made of quartz glass. A plurality of wafer mounting grooves 1a are cut and formed on the supporting member 1 formed of a quartz glass rod at a predetermined interval in the longitudinal direction. It is formed by cutting with a disc grinder or the like having a # 170 wheel.
[0027]
The quartz glass rod constituting the support member 1 may have a cross-sectional shape such as a circle, an ellipse, a square or a rectangle, and is not particularly limited. Usually, a rod-shaped member having a circular or square cross section is used.
[0028]
Next, the surface layer surface of the wafer mounting groove 1a as the cutting support portion in this embodiment will be described in detail below in comparison with the conventional example.
[0029]
Similar to the support member 1 of the wafer mounting portion 21, a cutting groove similar to the wafer mounting groove 1a is cut and formed on the peripheral surface of a plurality of quartz glass cylindrical rods, and the following three different treatments are performed. The surface layer of the cut groove was microscopically observed and compared.
[0030]
That is, using a quartz glass cylinder of 15 mmφ × 500 mm and a disk grinder having a diamond grinding wheel # 170 wheel, a pitch p = 4.8 mm and a groove width d = about 1 mm perpendicular to the axial direction as shown in FIG. Eighty cutting grooves 1b were formed.
[0031]
The cutting groove 1b thus formed was subjected to three types of treatment as follows.
(1) When a supporting member that does not perform any processing with the cutting groove 1b formed is formed, (2) The formed cutting groove 1b is annealed and supported by a mixed oxyhydrogen burner having a tip diameter of about 20 mm as in the conventional method. If you configure a member,
(3) When corresponding to the present embodiment example,
Three types of support members were prepared.
[0032]
In the case (3) corresponding to the present embodiment example, the processing by the burner will be described in detail.
(3) In the case, the cutting groove 1b was heat-treated by gas firing to the extent that the bottom and upper and lower surfaces of the cutting groove 1b were not melted with a mixed oxyhydrogen burner having a tip diameter of about 0.5 mmφ. .
Processing conditions in the burner processing will be described below.
1) Time: Heated for 4.5 to 5.5 seconds per cutting groove 1b. When the time is shorter than 4.5 seconds, the treatment is insufficient, and when the time is longer than 5.5 seconds, the end of the cutting groove 1b starts dripping and the finishing accuracy deteriorates.
[0033]
2) Gas flow rate: Hydrogen gas is 2.5 liters / minute to 4.0 liters / minute (optimum value is 3.3 liters / minute), and oxygen gas is 1.3 liters / minute to 2.0 liters / minute. Min (optimum value is 1.7 l / min). If the gas flow rate is too large, the flame tip becomes too large and the end of the cutting groove 1b begins to droop, and if the gas flow rate is too small, the processing becomes insufficient.
[0034]
3) Processing temperature: Although it depends on the gas flow rate, if it is roughly 1800 ° C. to 2000 ° C. or higher, the end of the cutting groove 1b begins to bend and the finishing accuracy deteriorates.
[0035]
As the burner used for the heat treatment of this embodiment, a burner having a tip diameter that is about 1/2 to 2 times the groove width d of the cutting groove 1b is preferably used. The oxyhydrogen burner may be either a mixed burner or a diffusion burner. However, the mixed oxyhydrogen burner is preferable in terms of easy control of the tip diameter.
[0036]
Next, in the cases (1), (2), and (3) described above, the comparison results of external observations using a scanning electron microscope (hereinafter abbreviated as SEM) are shown in the SEM photographs and tables shown in FIGS. It is shown in 1.
[0037]
Appearance observation by SEM was performed by (a) observation of the surface portion and (b) observation of the cross-section portion. A sample for appearance observation by SEM was prepared as follows.
[0038]
In FIG. 4 (a), incision is made in the direction of arrow A from the side facing the bottom of the cutting groove 1b to a point P1 near the bottom of the cutting groove 1b by using a disk grinder having a diamond grindstone wheel. In order to avoid the powder from cutting adhering to the vicinity, the remaining portion is broken and cut without using a disk grinder. Next, in FIG.4 (b), the convex part 1c is advanced to the position shown by the point P2 in the direction of arrow B, it cuts, and the remaining part is similarly broken and cut | disconnected. FIG.4 (c) shows the test piece of the supporting member 1 produced for observing the surface part 1d and the cross-sectional part 1e. The observation of the surface portion 1d and the cross-sectional portion 1e is performed from the direction of arrow C in FIG.
[0039]
5 and 6 are SEM photographs in the case of (1) described above, that is, in the case of this embodiment, and FIG. 5 (a) shows the surface portion 1d viewed from the direction of arrow C in FIG. 4 (c). FIG. 5B is a photograph taken by enlarging the surface portion 1d. FIG. 6A is a photograph of the cross section 1e, and FIG. 6B is a photograph of the cross section 1e enlarged.
[0040]
Similarly, FIGS. 7 and 8 are SEM photographs in the case of (2) above, and FIGS. 9 and 10 are SEM photographs in the case of (1) above.
[0041]
[Table 1]

The following is recognized from the photographs of FIGS. 5 to 10 and the results of Table 1.
In the case of (1), it is recognized that innumerable fine cracks exist in the cut surface layer portion of the support member 1 as it is cut, and innumerable cracks exceeding about 50 μm exist in the vertical direction.
[0042]
Further, in the case of (2), in the cutting surface layer portion of the support member 1 subjected to the conventional annealing treatment, the surface tip of a fine crack of several microns is rounded compared to the untreated one in the case of (1). However, although the cracks in the vertical direction are similarly rounded on the surface, it is recognized that some of them have a sharp tip part or the deepest part with a branching part of 50 μm or more. .
[0043]
In the case of this embodiment example (3), fine cracks disappear in the cut surface layer portion of the support member 1 and the surface is extremely flattened. At the same time, there are no cracks exceeding 50 μm in the vertical direction, and the entire surface is round and curved. In addition, it is recognized that there is no sharp tip portion in the deep direction, and the recess is substantially V-shaped.
[0044]
In Table 1, in the case of (1), the grindstone remains and a whitish appearance was exhibited. Here, the whitish appearance reflects a tendency to easily release dust and the like. In the case of (2), transparency was recognized as compared with (1), but a whitish appearance was recognized as compared with the peripheral surface. In the case of (3) corresponding to this embodiment, transparency was recognized in substantially the same manner as the peripheral surface.
[0045]
Next, the results of comparing the present embodiment example with the comparative example using the LPCVD apparatus will be described.
[0046]
Using the LPCVD apparatus shown in FIG. 2 or FIG. 10, the wafer support device 20 was disposed in the wafer device portion 21 constituted by the support member 1 and the upper and lower end plates as described above.
[0047]
Further, as the support member 1, the support member 1 obtained by cutting and forming the cutting support portion 1a in the quartz glass column in each of the above cases (1), (2), and (3) was used. Using an LPCVD apparatus configured using such a support member 1, monosilane gas is thermally decomposed under conditions of a film forming temperature of 650 ° C. and a film forming pressure of 0.2 Torr (= 26.7 Pa). A polysilicon film was deposited by 5 μm on the 150 mmφ semiconductor wafer 23 placed on the cutting support portion 1 a of the support member 1.
[0048]
After processing using each supporting member, each wafer mounting part 21 was taken out, the amount of particles on the semiconductor wafer was measured with a particle counter by a laser scattering method, and the amount of contamination was evaluated by the number.
[0049]
Moreover, the peeling resistance of the polysilicon film formed on the cutting support part 1a of each support member 1 was evaluated. The peel resistance evaluation was carried out by repeatedly repeating a thermal cycle test for one cycle by raising the temperature to 600 ° C. after holding at room temperature for 30 minutes and then cooling to room temperature again. Each time this thermal cycle was repeated 5 times, it was carried out while confirming the surface of each cutting support 1a with an optical microscope, and the peel resistance was shown by the number of thermal cycles in which the occurrence of peeling of the coating was confirmed.
[0050]
Further, the other support members constituting each wafer support portion 21 were used, and the polysilicon film was washed and removed using a mixed solution of hydrofluoric acid and nitric acid to evaluate the cleanability and erosion resistance. Detergency and erosion resistance were evaluated by SEM. These results are shown in Table 2.
[0051]
[Table 2]

In the case of this embodiment example (3), when the semiconductor wafer is placed on each support member 1 and the polysilicon film is formed thereon, the surface of the support member 1 is smooth with no fine cracks remaining, and is observed by SEM. Using a burner with a small tip diameter so as to have a shallow V-shaped concave portion that spreads upward with a gentle curved surface from the bottom, with substantially no internal progressive crack remaining in the cross section, the surface of the cutting support portion The entire surface of the layer is heat-treated evenly. In the case of (3), in the case of (1) using an untreated support member that does not treat the cutting support part at all, or in the case of (2) using a support member that has been subjected to annealing treatment of conventional gas firing In comparison, it is recognized that the generation of particles that contaminate the semiconductor wafer is drastically reduced, and the peel resistance is greatly improved. In the case of (3), the removal of the film is high due to the acid cleaning, and there is no remaining film piece that may be scattered later on the cutting support part. Further, erosion by strong acid such as hydrofluoric acid is not caused. It can be seen that the degree is also significantly reduced.
[0052]
As described above, according to the configuration of the present embodiment, the surface layer surface of the wafer mounting groove 1a obtained by cutting the quartz glass rod for mounting and supporting the semiconductor wafer 23 is subjected to predetermined heat treatment. Concave portions with smooth curved edges are scattered on the surface, which improves the adhesion of the coating and at the same time makes it easy to remove the coating without leaving any residue during acid cleaning. it can. As a result, in the semiconductor wafer processing step, the generation of particles that contaminate the semiconductor wafer can be remarkably suppressed, and the degree of erosion is significantly reduced in the acid cleaning, facilitating the removal of the film formed on the member. Can do.
[0053]
【The invention's effect】
As described above, according to the configuration of the present invention, the surface layer surface of the cutting support portion is scattered with concave portions having smooth curved edges, so that dust contamination can be sufficiently prevented and stable for a long time. Thus, a semiconductor wafer processing jig that can be used can be provided.
[Brief description of the drawings]
FIG. 1 is an explanatory front view showing a semiconductor wafer processing jig of the present invention.
FIG. 2 is an explanatory view schematically showing a configuration of a vertical LPCVD apparatus used in an example of the present invention.
FIG. 3 is a cross-sectional view showing a schematic configuration of a cutting support portion of a support member.
FIGS. 4A and 4B are cross-sectional views (a) and (b) showing a preparation procedure of a sample for observing the surface layer portion of a cutting support portion (wafer mounting groove) of the support member, and a perspective view showing an observation sample (c) ).
FIG. 5 is a scanning type with a magnification of 250 times (a) and 3000 times (b) of the fine structure of the surface portion 1d in FIG. 4C of the cutting support portion of the quartz glass support member of the embodiment of the present invention. Electron micrograph.
FIG. 6 is a scanning electron having a magnification of 250 times (a) and 3000 times (b) of the microstructure of the cross-sectional view 1e in FIG. 4C of the cutting support portion of the quartz glass support member of the embodiment of the present invention. Photomicrograph.
FIGS. 7A and 7B are scanning electron micrographs of magnifications 250 times (a) and 3000 times (b) of a microstructure of a surface portion of a cutting support portion of a conventional quartz glass support member.
FIGS. 8A and 8B are scanning electron micrographs of magnifications 250 times (a) and 3000 times (b) of a microstructure of a cross-sectional portion of a cutting support portion of a conventional quartz glass support member.
FIGS. 9A and 9B are scanning electron micrographs of magnifications of 250 times (a) and 3000 times (b) of the microstructure of the untreated surface portion of the cutting support portion of the quartz glass support portion.
FIGS. 10A and 10B are scanning electron micrographs of magnifications of 250 times (a) and 3000 times (b) of a microstructure of a cross-sectional portion of an untreated surface of a cutting support portion of a quartz glass support member.
FIG. 11 is an explanatory diagram schematically showing a configuration of a general vertical LPCVD apparatus.
[Explanation of symbols]
1 Wafer Support 1a Cutting Support (Wafer Mounting Groove)
1c Convex part 1b Cutting groove 1d Surface part 1e Cross-section part 2 Connecting member 10 Reaction tube 11 Reaction outer tube 12 Reaction inner tube 13 Manifold 14 Gas introduction tube 15 Gas discharge tube 16 Vacuum pump 17 Resistance heater 18 Capping ruffle 20 Wafer support device 21 Wafer mounting portion 22 Insulating cylinder 23 Semiconductor wafer 24 Wafer support device rotating mechanism

Claims (2)

In a semiconductor wafer processing jig used to support a semiconductor wafer in the processing of a semiconductor wafer,
A support member for supporting a semiconductor wafer is provided, and the support member has a cutting support part for placing the semiconductor wafer formed by cutting.
The surface layer of the cutting support is flattened,
Concave portions are scattered on the surface layer of the cutting support portion,
In the SEM observation of a cross section in a plane perpendicular to the traveling direction of a grinder or the like during cutting, the concave portion is substantially V-shaped and gently spreads in a bowl shape from the bottom without constricting the middle or branching the tip. Ri Do from the shape,
The recess has a depth of 1 μm to 50 μm,
The ratio W / D between the depth D of the recess and the width W at a depth position of 2D / 3 from the upper surface of the recess is 0.2 or more,
The semiconductor wafer processing jig , wherein 1 to 50 recesses are scattered per 100 μm length range on a surface layer surface of the cutting support portion . In a semiconductor wafer processing jig used to support a semiconductor wafer in the processing of a semiconductor wafer,
A support member for supporting a semiconductor wafer is provided, and the support member has a cutting support part for placing the semiconductor wafer formed by cutting.
The surface layer of the cutting support is flattened,
Concave portions are scattered on the surface layer of the cutting support portion,
In the SEM observation of a cross section in a plane perpendicular to the traveling direction of a grinder or the like during cutting, the concave portion is substantially V-shaped and gently spreads in a bowl shape from the bottom without constricting the middle or branching the tip. is heat-treated at a gas burner to consist of shape you is,
The recess has a depth of 1 μm to 50 μm,
The ratio W / D between the depth D of the recess and the width W at a depth position of 2D / 3 from the upper surface of the recess is 0.2 or more,
The semiconductor wafer processing jig , wherein 1 to 50 recesses are scattered per 100 μm length range on a surface layer surface of the cutting support portion .

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