JPH05291264A - Semiconductor substrate and manufacture thereof - Google Patents

Semiconductor substrate and manufacture thereof

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Publication number
JPH05291264A
JPH05291264A JP11689192A JP11689192A JPH05291264A JP H05291264 A JPH05291264 A JP H05291264A JP 11689192 A JP11689192 A JP 11689192A JP 11689192 A JP11689192 A JP 11689192A JP H05291264 A JPH05291264 A JP H05291264A
Authority
JP
Japan
Prior art keywords
wafer
film
wet
sandblasting
semiconductor substrate
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.)
Granted
Application number
JP11689192A
Other languages
Japanese (ja)
Other versions
JP2820230B2 (en
Inventor
Shigechika Nezu
茂義 祢津
Shinichi Tomizawa
進一 富沢
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shin Etsu Handotai Co Ltd
Original Assignee
Shin Etsu Handotai Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Shin Etsu Handotai Co Ltd filed Critical Shin Etsu Handotai Co Ltd
Priority to JP11689192A priority Critical patent/JP2820230B2/en
Priority to DE1992627158 priority patent/DE69227158T2/en
Priority to EP19920111576 priority patent/EP0525455B1/en
Publication of JPH05291264A publication Critical patent/JPH05291264A/en
Application granted granted Critical
Publication of JP2820230B2 publication Critical patent/JP2820230B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

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Abstract

PURPOSE:To obtain introduction of a rear surface distortion layer having a sustainable EG effect into a high temperature heat treatment in the steps of manufacturing a device with less mechanical damage of a rear surface of a wafer by providing an inorganic film on the rear surface of the wafer by a wet method and then processing it by a sandblasting method. CONSTITUTION:After an inorganic film by a wet method is provided on a rear surface of an Si single crystal wafer W to an opposite side to a mirror surface, it is processed by a sandblasting method. A method for forming the film by the wet method includes, for example, a wet oxidizing method, an anodizing method or a liquid phase film growing method. For example, an electrolytic device as shown in the drawing is used, and as electrolyte, KNO3 of 0.1mol/l is dissolved in 5wt.% of aqueous ethylene glycol solution, it is electrolytically processed by a current density of 30mA/cm<2> for 5min, and only one side of the wafer W is anodized. Then, it is cleaned with pure water, dried, and then wet sandblasted from above the anodized film.

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【産業上の利用分野】本発明は、半導体基板及びその製
造方法に関し、特にSi単結晶ウェーハ(以下ウェーハ
という)の鏡面とは反対側の裏面(以下単に裏面とい
う)の機械的損傷(Fracture) が少なく、かつ半導体装
置(以下デバイスという)製造時に、エクストリンシッ
クゲッタリング(以下EGという)効果が持続的である
半導体基板及びその製造方法に関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor substrate and a method for manufacturing the same, and more particularly to mechanical damage (Fracture) on the back surface (hereinafter simply referred to as the back surface) of the Si single crystal wafer (hereinafter referred to as the wafer) opposite to the mirror surface. The present invention relates to a semiconductor substrate and a method of manufacturing the semiconductor substrate, which has a small amount and has a continuous extrinsic gettering (hereinafter referred to as EG) effect during manufacturing of a semiconductor device (hereinafter referred to as a device).

【0002】[0002]

【従来の技術】デバイスの製造工程において、ウェーハ
は種々の熱処理を受け、その際結晶中の酸素や炭素、重
金属不純物等によって様々の結晶欠陥が誘起される。こ
れらの欠陥はウェーハの表面及び表面付近にも発生する
ため、リーク電流の増大をまねき、デバイス特性の劣化
と歩留りの低下をもたらす。
2. Description of the Related Art In a device manufacturing process, a wafer is subjected to various heat treatments, and various crystal defects are induced by oxygen, carbon and heavy metal impurities in the crystal. These defects also occur on the surface of the wafer and in the vicinity of the surface, leading to an increase in leak current, resulting in deterioration of device characteristics and a decrease in yield.

【0003】しかしながら、ウェーハの裏面またはウェ
ーハ内部に作った微小結晶欠陥や歪みは、デバイス特性
に有害な影響を与える不純物を捕獲、固着したり、また
は欠陥発生に関与している点欠陥などを除去する作用が
ある。この作用はゲッタリングと呼ばれ、前者はエクス
トリンシックゲッタリング(EG)、後者はイントリン
シックゲッタリング(IG)と呼ばれている。
However, fine crystal defects or strains formed on the back surface of the wafer or inside the wafer trap or fix impurities that adversely affect the device characteristics, or remove point defects that are involved in the generation of defects. There is an action. This action is called gettering, the former is called extrinsic gettering (EG) and the latter is called intrinsic gettering (IG).

【0004】このEGを付与する一つの手段として、ウ
ェーハの裏面に微粒子を吹きつけて歪層を導入し、デバ
イスの熱処理プロセスでこの裏面歪層に起因する転位や
積層欠陥を発生せしめ、これらをゲッタリング源として
利用する手法がサンドブラスト法として知られている
(特開昭53−128272号公報、特開昭54−14
8474号公報等)。
As one means of imparting this EG, fine particles are blown onto the back surface of the wafer to introduce a strained layer, and dislocations and stacking faults caused by this back strained layer are generated in the heat treatment process of the device. A method used as a gettering source is known as a sandblasting method (Japanese Patent Laid-Open Nos. 53-128272 and 54-14).
8474, etc.).

【0005】しかし、このサンドブラスト法の場合、ウ
ェーハ裏面に形成された歪層は、後のウェーハ加工工程
における洗浄や、デバイス製造時の高温熱処理に際して
消滅しやすく、デバイス製造工程の中途でEG効果を失
いやすい欠点がある。その改善策としてサンドブラスト
圧を高め、より深い歪層を形成させる方法もあるが、こ
の場合には前記導入が望ましい歪層とは異なる新たな機
械的損傷を発生し、この損傷はデバイス製造プロセスに
おいて発塵や、スリップ転位発生の原因となって、デバ
イスの特性やその製造歩留りを悪化させる原因となる。
However, in the case of this sand blasting method, the strained layer formed on the back surface of the wafer is likely to disappear during cleaning in a later wafer processing step and high temperature heat treatment during device manufacturing, and the EG effect is generated in the middle of the device manufacturing process. There is a drawback that is easy to lose. There is also a method of improving the sandblast pressure to form a deeper strained layer as an improvement measure, but in this case, the introduction causes new mechanical damage different from the desired strained layer, and this damage occurs in the device manufacturing process. This causes dust generation and slip dislocation generation, which causes deterioration of device characteristics and manufacturing yield.

【0006】[0006]

【発明が解決しようとする課題】本発明は、乾式又は湿
式のサンドブラスト処理によってウェーハの裏面に歪層
を導入するにあたり、ウェーハの裏面における機械的損
傷が少なく、かつ以後のウェーハ加工やこれを利用した
デバイス製造工程における高温熱処理において、持続性
あるEG効果を有する裏面歪層を導入した半導体基板及
びその製造方法を提供することを目的とする。
DISCLOSURE OF THE INVENTION In the present invention, when a strained layer is introduced into the back surface of a wafer by a dry or wet sandblasting process, there is little mechanical damage on the back surface of the wafer, and the subsequent wafer processing and the use thereof. It is an object of the present invention to provide a semiconductor substrate into which a back strain layer having a persistent EG effect is introduced in a high temperature heat treatment in the device manufacturing process described above, and a manufacturing method thereof.

【0007】[0007]

【課題を解決するための手段】上記課題を解決するため
に、本発明の半導体基板及びその製造方法においては、
ウェーハの裏面に湿式法による無機質膜を設け、次いで
サンドブラスト法により該ウェーハの裏面に歪層を導入
するようにしたものである。
In order to solve the above-mentioned problems, in the semiconductor substrate and the manufacturing method thereof according to the present invention,
An inorganic film is provided on the back surface of the wafer by a wet method, and then a strained layer is introduced on the back surface of the wafer by a sand blast method.

【0008】上記湿式法によるウェーハ表面への無機質
膜形成手段としては、(イ)湿式酸化法、(ロ)陽極酸
化法、(ハ)液相成膜法等を例示することができる
Examples of means for forming an inorganic film on the wafer surface by the above-mentioned wet method include (a) wet oxidation method, (b) anodic oxidation method, and (c) liquid phase film formation method.

【0009】(イ)湿式酸化法は、過酸化水素や硝酸、
硫酸のような液状酸化剤、または過マンガン酸やクロム
酸、過塩素酸のような固形酸化剤の水溶液、もしくは酸
との混合溶液中にウェーハを浸漬して酸化させる方法で
ある。しかして高純度ウェーハに対し、薬液中の不純物
による汚染を避けるためには、高純度でかつ安価な薬液
として、SiO2 を溶解しない酸化性の酸に過酸化水素
を添加した溶液を使用するのが望ましい。
(A) The wet oxidation method uses hydrogen peroxide, nitric acid,
This is a method of oxidizing a wafer by immersing it in a liquid oxidizing agent such as sulfuric acid, an aqueous solution of a solid oxidizing agent such as permanganic acid, chromic acid, or perchloric acid, or a mixed solution with an acid. Therefore, in order to avoid contamination of high-purity wafers by impurities in the chemical liquid, a solution of hydrogen peroxide added to an oxidizing acid that does not dissolve SiO 2 is used as a high-purity and inexpensive chemical liquid. Is desirable.

【0010】すなわちH2 SO4 +H2 2 ,HCl+
2 2 ,HNO3 +H2 2 等の混合水溶液にウェー
ハを、常温から数10℃の液温で、数分から場合により
数時間浸漬することにより、表面にSiO2 の薄膜を形
成させることができる。この場合の液組成は、H2 2
(30%過酸化水素水)1容に対し、希釈前の濃酸1〜
10容位に配合された濃度範囲で、必要に応じて更に水
で希釈された溶液が使用される。
That is, H 2 SO 4 + H 2 O 2 , HCl +
To form a thin film of SiO 2 on a surface by immersing a wafer in a mixed aqueous solution of H 2 O 2 , HNO 3 + H 2 O 2, etc. at room temperature to several tens of degrees Celsius for several minutes to possibly several hours. You can The liquid composition in this case is H 2 O 2
1 volume of (30% hydrogen peroxide solution) to 1% of concentrated acid before dilution
A solution, which is further diluted with water in the concentration range of about 10 volumes, is used if necessary.

【0011】(ロ)陽極酸化法はウェーハの鏡面となす
側に陽極を圧着し、そのウェーハ裏面を白金陰極と対向
させ、酸や水溶性の有機物質又は無機塩を溶解した電解
液中で直流を通じることにより、ウェーハの裏面側を陽
極酸化する。この方法によれば、ウェーハの片面側のみ
を選択的に膜付けできるという効果がある。使用される
酸は塩酸、弗酸、硝酸のような通常の酸、有機物質はエ
チルアルコール、エチレングリコール、メチルアセトア
ミド等、無機塩はNaNO3 ,KNO3 ,NH4 NO3
等の使用例がある。
(B) In the anodizing method, an anode is pressure-bonded to the side of the wafer that is the mirror surface, the back surface of the wafer is opposed to the platinum cathode, and a direct current is applied in an electrolytic solution in which an acid or water-soluble organic substance or inorganic salt is dissolved. By passing through, the back side of the wafer is anodized. According to this method, there is an effect that only one side of the wafer can be selectively coated with a film. The acids used are normal acids such as hydrochloric acid, hydrofluoric acid, nitric acid, organic substances such as ethyl alcohol, ethylene glycol, methylacetamide, etc., and inorganic salts such as NaNO 3 , KNO 3 , NH 4 NO 3
There are usage examples such as.

【0012】(ハ)液相成膜法は、液相中における化学
反応を利用した成膜法である。一例として、過飽和状態
のケイ弗化水素酸の水溶液に基板を浸漬し、これに反応
開始剤として金属Alを投入し、次の反応によりウェー
ハ表面上にSiO2 の膜を形成させることができる。
(C) The liquid phase film forming method is a film forming method utilizing a chemical reaction in the liquid phase. As an example, a substrate can be dipped in an aqueous solution of hydrofluoric silicic acid in a supersaturated state, metal Al can be added as a reaction initiator, and a SiO 2 film can be formed on the wafer surface by the following reaction.

【0013】[0013]

【化1】 [Chemical 1]

【0014】[0014]

【化2】 [Chemical 2]

【0015】この方法は、反応時におけるウェーハの固
定方法によって、片側面あるいは全表面を選択的に膜付
けすることができる。また、別の薬剤との組合せによる
反応により酸化膜以外の膜付けも可能である。
According to this method, one side surface or the entire surface can be selectively film-formed depending on the method of fixing the wafer during the reaction. Further, a film other than the oxide film can be attached by a reaction caused by a combination with another drug.

【0016】また上記各種の方法により形成される無機
質膜がサンドブラスト処理後において不要の時は、機械
的研磨若しくは弗酸を主体とする通常のエッチング液に
より容易に除去することができる。
When the inorganic film formed by the above various methods is unnecessary after sandblasting, it can be easily removed by mechanical polishing or an ordinary etching solution mainly containing hydrofluoric acid.

【0017】[0017]

【作用】本発明方法は、ウェーハ裏面に湿式法による無
機質膜を介在させてサンドブラスト処理を行うことによ
って、従来のウェーハ裏面に微粒子(サンド)を直接吹
きつけるサンドブラスト処理を行う場合に問題となるウ
ェーハの機械的損傷を効果的に防止するものである。
The method of the present invention is a problem when performing a conventional sandblasting process in which fine particles (sands) are directly blown to the backside of a wafer by performing a sandblasting process on the backside of the wafer with an inorganic film interposed by a wet method. It effectively prevents the mechanical damage of.

【0018】特に乾式サンドブラスト法で、使用する微
粒子が粉砕された硬質材料である場合、その微粒子の突
端が高速度でウェーハ表面に衝突し、微粒子の運動エネ
ルギーはウェーハ表面に対する破壊力となって、しばし
ばウェーハ面に局所的な破砕、または表面上に微細なク
ラックを伴うことが多かった。この現象を緩和するため
湿式サンドブラスト法が提案されるが、同法によっても
満足できる結果は得られていない。
Particularly in the dry sandblast method, when the fine particles to be used are crushed hard materials, the tips of the fine particles collide with the wafer surface at a high speed, and the kinetic energy of the fine particles becomes a destructive force on the wafer surface. It was often accompanied by local fractures on the wafer surface or fine cracks on the surface. Wet sandblasting has been proposed to mitigate this phenomenon, but satisfactory results have not been obtained even with this method.

【0019】すなわち本発明の無機質膜の存在は、その
適宜な膜厚によって前記破壊力を膜内に吸収し、ウェー
ハには及ぼさない利点がある。そのために無機質膜に要
求される条件は、ある程度の硬度と膜自身のウェーハに
対する密着性、破壊力に対する耐久性の他、膜質によっ
ては膜厚の調整も必要である。そしてこれらの要件を勘
案すれば、本発明の湿式法による無機質膜は極めて好適
な材料であるといえる。
That is, the presence of the inorganic film of the present invention has an advantage that the destructive force is absorbed in the film by the appropriate film thickness and does not reach the wafer. Therefore, the conditions required for the inorganic film include a certain level of hardness, adhesion of the film itself to the wafer, durability against destructive force, and adjustment of the film thickness depending on the film quality. Considering these requirements, it can be said that the inorganic film by the wet method of the present invention is a very suitable material.

【0020】更に本発明は、上記の主たる作用効果の他
に、次のような作用効果をも達成する。
Further, the present invention achieves the following operational effects in addition to the main operational effects described above.

【0021】(a)デバイス製造時において、持続性の
あるEG効果を有する半導体基板を得ることができる。
(A) A semiconductor substrate having a persistent EG effect can be obtained during device manufacturing.

【0022】その理由は前述のように、従来のサンドブ
ラスト処理においては、微粒子によるウェーハ裏面の機
械的損傷の問題を避けるため、所望の歪層を形成させる
に至らないケースが多かったが、ウェーハ裏面に無機質
膜を設けることにより、その裏面にサンドブラストによ
る強力な機械的エネルギーの付与が可能となり、結果と
してEG効果が従来法のレベル以上に発揮されるように
なったことであり、この効果はサンドブラスト後、無機
質膜を除去しても減るものではない。この場合は無機質
膜除去工程が増えるだけで、大きな工程の変更は必要と
しない。
As described above, in the conventional sandblasting process, there are many cases in which the desired strained layer cannot be formed in order to avoid the problem of mechanical damage on the back surface of the wafer due to fine particles. By providing an inorganic film on the back surface, it is possible to apply strong mechanical energy to the back surface by sandblasting, and as a result, the EG effect can be exerted above the level of the conventional method. After that, even if the inorganic film is removed, it does not decrease. In this case, the number of steps for removing the inorganic film is increased, and no major change in the steps is required.

【0023】(b)また、サンドブラスト終了後、ウェ
ーハ裏面に無機質膜を残したままの半導体基板を使用し
てデバイスの製造を行う場合、種々の熱処理工程が存在
するにもかかわらず、無機質膜とウェーハの界面近傍に
形成された歪層は、無機質膜の影響を受けて修復困難な
状態にあり、従って、無機質膜とウェーハ間の結合力が
強い程、EG効果の持続性は保たれるものと推定され
る。
(B) In addition, after the sandblasting, when a device is manufactured using a semiconductor substrate in which the inorganic film is left on the back surface of the wafer, despite the various heat treatment steps, The strained layer formed near the interface of the wafer is in a state of being difficult to repair due to the influence of the inorganic film, and therefore, the stronger the bonding force between the inorganic film and the wafer, the more the EG effect is maintained. It is estimated to be.

【0024】(c)なお、無機質膜を除去しない場合に
は、上述の効果の外に次のような利点がある。すなわ
ち、
(C) If the inorganic film is not removed, there are the following advantages in addition to the above effects. That is,

【0025】半導体基板を、たとえばノーワックス法
で鏡面研磨仕上げする場合に、無機質膜の存在により基
板と研磨装置の保持面との固定は容易となる。 半導体基板の処理を行う場合に工程間または貯蔵時に
おけるカセット等に起因する基板表面の汚染が防止され
る。 半導体基板に起因するパーテイクルの発生が防止され
る。
When a semiconductor substrate is mirror-polished by, for example, a waxless method, the presence of the inorganic film facilitates the fixing of the substrate and the holding surface of the polishing apparatus. When processing a semiconductor substrate, contamination of the substrate surface due to a cassette or the like between steps or during storage is prevented. Generation of particles due to the semiconductor substrate is prevented.

【0026】(d)湿式法における無機質膜の形成法
は、いずれも水溶液中における化学的反応を応用した手
法であり、CVD法や熱酸化法のように数100℃から
1000℃以上の高熱処理を必要とせず、通常の室温か
らせいぜい数10℃の水溶液中において膜付けができる
ことから、高温反応に伴う高価な設備を不要とし、かつ
エネルギーを節約できるとともに、熱処理に伴うウェー
ハ汚染や、欠陥発生を抑制することができる等の利点が
あって、今日見直されつつある成膜方法である。
(D) The inorganic film forming method in the wet method is a method in which a chemical reaction in an aqueous solution is applied, and a high heat treatment of several 100 ° C. to 1000 ° C. or more like a CVD method or a thermal oxidation method. Since it is possible to form a film in an aqueous solution from ordinary room temperature to several tens of degrees Celsius at the most, it does not require expensive equipment for high temperature reaction, saves energy, and also causes wafer contamination and defect generation due to heat treatment. It is a film forming method which is being reviewed today because it has the advantage of suppressing

【0027】[0027]

【実施例】以下に本発明の実施例を挙げて説明する。EXAMPLES Examples of the present invention will be described below.

【0028】実施例1,2、及び比較例1 (試験に使用のウェーハ)CZ法による引上軸方向<1
00>、p型で抵抗率12〜20Ω・cm、直径125
mmのSi単結晶棒を円板状に切断(スライス)した
後、面取り、ラッピング、エッチング等の工程により製
造された、厚さ620μmのウェーハを15枚用意し
た。
Examples 1 and 2, and Comparative Example 1 (Wafer used for test) Pull-up axial direction by CZ method <1
00>, p-type, resistivity 12 to 20 Ω · cm, diameter 125
Fifteen wafers with a thickness of 620 μm prepared by cutting (slicing) a Si single crystal rod of mm into a disc shape and then performing chamfering, lapping, etching and the like were prepared.

【0029】(工程の説明) (1)15枚のウェーハのうち5枚を未処理のまま、そ
の片側面を湿式サンドブラスト処理し、これを比較例1
とした。 (2)15枚のウェーハの残り10枚を、容積比で過酸
化水素(30%):硫酸:H2 O=3:1:4の混合溶
液中に浸漬し、30℃で15分間処理した後、これを純
水で洗浄し乾燥させた。ウェーハ表面上に形成された酸
化膜の厚さを、エリプソメーターで測定した所、80〜
105Åであった。 その後(1)と同一条件で、その片側面の膜上より湿式
サンドブラスト処理し、同処理後のウェーハ5枚を実施
例1とした。
(Description of Processes) (1) Five of the 15 wafers were untreated, one side surface thereof was subjected to wet sandblasting, and this was used as Comparative Example 1.
And (2) The remaining 10 wafers of 15 wafers were immersed in a mixed solution of hydrogen peroxide (30%): sulfuric acid: H 2 O = 3: 1: 4 in volume ratio and treated at 30 ° C. for 15 minutes. Then, this was washed with pure water and dried. When the thickness of the oxide film formed on the wafer surface was measured by an ellipsometer, it was 80-
It was 105Å. Then, under the same conditions as in (1), wet sandblasting was performed on the film on one side of the film, and 5 wafers after the same treatment were used as Example 1.

【0030】(3)(2)の方法で湿式サンドブラスト
処理を行った残り5枚のウェーハを、希弗酸で処理して
酸化膜を除去し、洗浄乾燥させたものを実施例2とし
た。なお上記湿式サンドブラストにおいて、サンドは平
均粒子径が薬5μmの石英微粉末を使用し、噴射圧は
1.0kg/cm2 以外の諸条件は統一して試験を行っ
た。
(3) The remaining 5 wafers that had been wet sandblasted by the method of (2) were treated with dilute hydrofluoric acid to remove the oxide film, and then washed and dried as Example 2. In the above wet sandblasting, the sand was made of quartz fine powder having an average particle diameter of 5 μm, and the injection pressure was 1.0 kg / cm 2 except for various conditions, and the test was conducted.

【0031】上記工程により処理された各ウェーハに対
し、次の検査を行った。 OSF(酸化誘起積層欠陥)の測定 ウェーハを酸素雰囲気中1100℃/60分の熱酸化処
理を行った後、酸化膜をセコエッチング液で除去し、ウ
ェーハ表面に析出したOSFの数を光学顕微鏡により計
測した。
The following inspections were performed on each wafer processed by the above steps. Measurement of OSF (Oxidation Induced Stacking Fault) After performing a thermal oxidation process on the wafer in an oxygen atmosphere at 1100 ° C./60 minutes, the oxide film was removed with a Secco etching solution, and the number of OSFs deposited on the wafer surface was measured by an optical microscope. Measured.

【0032】機械的損傷の数 OSF試験のためセコエッチングされたウェーハ表面
を、走査型電子顕微鏡による1500倍の倍率で、1方
向長さ100mmの十字型で走査することにより観察さ
れる傷の数を計測した。
Number of Mechanical Damage The number of scratches observed by scanning a Secco-etched wafer surface for the OSF test with a scanning electron microscope at a magnification of 1500 × with a cross shape having a length of 100 mm in one direction. Was measured.

【0033】機械的損傷の深さ 損傷部分についてアングルポリッシュ法により、その深
さを測定した。
Depth of Mechanical Damage The depth of the damaged portion was measured by the angle polish method.

【0034】(試験結果)表1にその結果を示す。(Test Results) The results are shown in Table 1.

【0035】[0035]

【表1】 [Table 1]

【0036】表1の結果から、OSF密度は従来法(比
較例1)と本発明法(実施例1及び2)において実質的
な差はないが、機械的損傷の数とその深さについて、顕
著な改善がみられる。また酸化膜を残した実施例1の方
が、それを除去した実施例2の場合よりOSF密度が高
いのは、膜の有無が影響したものであると推定される。
From the results shown in Table 1, there is no substantial difference in OSF density between the conventional method (Comparative Example 1) and the method of the present invention (Examples 1 and 2), but the number of mechanical damages and the depth thereof are as follows: Significant improvement is seen. Further, it is presumed that the OSF density in Example 1 in which the oxide film was left was higher than that in Example 2 in which the oxide film was removed, probably because of the presence or absence of the film.

【0037】実施例3,4、及び比較例2 (試験に使用のウェーハ)実施例1,2、及び比較例1
で使用のウェーハと同一のもの15枚を使用した。なお
以下の試験で適用されるサンドブラストの諸条件や、サ
ンドブラスト後の検査方法も同様である。
Examples 3, 4 and Comparative Example 2 (Wafer used for test) Examples 1, 2 and Comparative Example 1
Fifteen identical wafers were used. The same applies to the various conditions of sandblast applied in the following tests and the inspection method after sandblasting.

【0038】(工程の説明) (4)15枚のウェーハのうち5枚を未処理のまま、そ
の片側面を湿式サンドブラスト処理し、これを比較例2
とした。
(Explanation of Process) (4) Wet sandblasting was applied to one side of 5 wafers out of 15 wafers, which was not treated.
And

【0039】(5)残り10枚のウェーハについて、次
の方法と条件でウェーハの片面側のみを陽極酸化した。
すなわち図1で模式的に示すような、底面は陽極となる
平坦な白金板2と、弗素樹脂の側壁部3で構成される縦
長の電解槽1において、白金板2上に陽極酸化処理され
るウェーハWを載置し、その真上部に弗素樹脂製の電解
液攪拌装置4と、ウェーハWから離れた電解液6面に近
い上方部に白金製リング状の陰極5で構成される電解装
置を使用した。
(5) With respect to the remaining 10 wafers, only one side of the wafer was anodized by the following method and conditions.
That is, as shown schematically in FIG. 1, a platinum plate 2 having a flat bottom surface serving as an anode and a side wall 3 of a fluororesin in a vertically elongated electrolytic cell 1 are anodized on the platinum plate 2. A wafer W is placed, an electrolytic solution stirring device 4 made of a fluororesin is provided immediately above the wafer W, and an electrolytic device composed of a platinum ring-shaped cathode 5 is provided at an upper portion near the surface of the electrolytic solution 6 apart from the wafer W. used.

【0040】電解液は、5重量%のエチレングリコール
水溶液に0.1mol/l濃度のKNO3 を溶解させた
ものを使用し、電流密度30mA/cm2 で5分間の電
解処理を行い、その後純水で洗浄し乾燥した。
An electrolytic solution prepared by dissolving KNO 3 at a concentration of 0.1 mol / l in a 5% by weight ethylene glycol aqueous solution was used, and electrolysis was performed at a current density of 30 mA / cm 2 for 5 minutes, and then pure water was used. It was washed with water and dried.

【0041】陽極酸化されたウェーハ表面は多孔質の酸
化物層で、その一部を劈開して断面を光学顕微鏡で観察
し、多孔質層の厚さを測った所、約450〜600Åで
あった。その後(4)と同一条件で、その膜上より湿式
サンドブラスト処理を行い、その5枚を実施例3とし
た。
The surface of the anodized wafer was a porous oxide layer, a part of which was cleaved and the cross section was observed with an optical microscope. When the thickness of the porous layer was measured, it was about 450 to 600Å. It was Then, under the same conditions as in (4), wet sandblasting treatment was performed on the film, and five of them were used as Example 3.

【0042】(6)(5)の方法で湿式サンドブラスト
処理を行った残り5枚のウェーハを、希弗酸で処理して
酸化膜を除去し、洗浄乾燥させたものを実施例4とし
た。
(6) The remaining 5 wafers that had been wet-sandblasted by the methods (5) were treated with dilute hydrofluoric acid to remove the oxide film, and then washed and dried as Example 4.

【0043】(試験結果)表2にその結果を示す。(Test Results) Table 2 shows the results.

【0044】[0044]

【表2】 [Table 2]

【0045】実施例1及び2の場合と同じ傾向が見られ
るが、実施例3及び実施例4の場合、OSF密度や機械
的損傷の度合は低くなっている。その理由としては、形
成された膜が厚いことに加え、その形状や性質の差が影
響したものと推定される。
The same tendency as in the case of Examples 1 and 2 is observed, but in the case of Examples 3 and 4, the OSF density and the degree of mechanical damage are low. It is presumed that the reason for this is that the formed film is thick and that the difference in shape and properties affects it.

【0046】実施例5,6、及び比較例3 (試験に使用のウェーハ)実施例1,2、及び比較例1
で使用のウェーハと同一のもの15枚を使用した。なお
以下の試験で適用されるサンドブラストの諸条件や、サ
ンドブラスト後の検査方法も同様である。
Examples 5, 6 and Comparative Example 3 (Wafer used for test) Examples 1, 2 and Comparative Example 1
Fifteen identical wafers were used. The same applies to the various conditions of sandblast applied in the following tests and the inspection method after sandblasting.

【0047】(工程の説明) (7)15枚のウェーハのうち5枚を未処理のまま、そ
の片側面を湿式サンドブラスト処理し、これを比較例3
とした。
(Description of Processes) (7) Wet sandblasting is applied to one side of 5 wafers out of 15 wafers, which is not treated.
And

【0048】(8)残り10枚のウェーハについて、次
の方法による液相成膜法によりウェーハ表面にSiO2
層を形成させた。すなわち、ポリプロピレン製の循環濾
過装置を備えた浸漬槽に、10枚のウェーハのほぼ全面
が処理液の流れと平行に接触する構造の支持具により縦
方向等間隔に並べ固定した。
(8) With respect to the remaining 10 wafers, SiO 2 was formed on the wafer surface by the liquid phase film forming method according to the following method.
A layer was formed. That is, in a dipping tank equipped with a polypropylene circulation filter, ten wafers were arranged and fixed at equal intervals in the vertical direction by a support tool having a structure in which almost the entire surface of the wafer was in contact with the flow of the processing liquid in parallel.

【0049】その状態で、濃度約3.5mol/lのH
2 SiF6 、温度40℃の処理液を所定の流速で循環さ
せながら、反応開始剤として高純度Alの平板を、ウェ
ーハ並び方向の手前で処理液の上流側に浸漬せしめ、1
5分間処理を行った。
In that state, H at a concentration of about 3.5 mol / l
2 While circulating the processing solution of SiF 6 at a temperature of 40 ° C. at a predetermined flow rate, a flat plate of high-purity Al as a reaction initiator is immersed in the upstream side of the processing solution before the wafer alignment direction.
The treatment was carried out for 5 minutes.

【0050】処理が終わったウェーハは、純水で洗浄し
て後乾燥し、ウェーハ表面に形成されたSiO2 の膜厚
をエリプソメーターで測定した所、95〜110Åであ
った。この膜付けウェーハ10枚の片側面を、(7)と
同一条件で湿式サンドブラスト処理し、その5枚を実施
例5とした。
The treated wafer was washed with pure water and then dried, and the film thickness of SiO 2 formed on the wafer surface was measured by an ellipsometer to be 95 to 110Å. One side surface of the 10 film-coated wafers was subjected to wet sandblasting under the same conditions as (7), and 5 of them were taken as Example 5.

【0051】(9)(8)の方法で湿式サンドブラスト
処理を行った残り5枚のウェーハを、希弗酸で処理して
酸化膜を除去し、洗浄乾燥させたものを実施例6とし
た。
(9) The remaining 5 wafers that had been wet sandblasted by the methods (8) were treated with dilute hydrofluoric acid to remove the oxide film, and washed and dried as Example 6.

【0052】(試験結果)表3にその結果を示す。(Test Results) The results are shown in Table 3.

【0053】[0053]

【表3】 [Table 3]

【0054】実施例1及び2、実施例3及び4と同様の
傾向が認められるが、これらと比較して機械的損傷の度
合が高いのは、膜の性状が影響したものであると推定さ
れる。
Although the same tendency as in Examples 1 and 2 and Examples 3 and 4 is recognized, the higher degree of mechanical damage compared to these is presumed to be due to the properties of the film. It

【0055】[0055]

【発明の効果】以上述べたごとく、本発明によれば、乾
式又は湿式のサンドブラスト処理によってウェーハの裏
面に歪層を導入するにあたり、ウェーハの裏面における
機械的損傷が少なく、かつデバイス製造工程における高
温熱処理において、EG効果の持続性ある裏面歪層を導
入した半導体基板を製造することができる。
As described above, according to the present invention, when a strained layer is introduced into the back surface of a wafer by dry or wet sandblasting, there is little mechanical damage on the back surface of the wafer and the high temperature in the device manufacturing process. It is possible to manufacture a semiconductor substrate into which a back strain layer having a persistent EG effect is introduced by heat treatment.

【図面の簡単な説明】[Brief description of drawings]

【図1】実施例3及び4における陽極酸化処理に用いた
電解装置の概略断面図である。
FIG. 1 is a schematic cross-sectional view of an electrolysis apparatus used for anodizing treatment in Examples 3 and 4.

【符号の説明】[Explanation of symbols]

1 電解槽 2 白金板(陽極) 3 側壁部 4 電解液攪拌装置 5 リング状陰極 6 電解液 1 Electrolyte Tank 2 Platinum Plate (Anode) 3 Sidewall 4 Electrolyte Stirrer 5 Ring Cathode 6 Electrolyte

Claims (4)

【特許請求の範囲】[Claims] 【請求項1】 Si単結晶ウェーハの鏡面とは反対側の
裏面に湿式法による無機質膜を設けて後、サンドブラス
ト法による処理を施したことを特徴とする半導体基板。
1. A semiconductor substrate characterized by being provided with an inorganic film by a wet method on the back surface of the Si single crystal wafer opposite to the mirror surface, and then treated by a sandblast method.
【請求項2】 湿式法による無機質膜を形成する方法
が、湿式酸化法、陽極酸化法若しくは液相成膜法である
ことを特徴とする請求項1記載の半導体基板。
2. The semiconductor substrate according to claim 1, wherein the method for forming the inorganic film by the wet method is a wet oxidation method, an anodic oxidation method or a liquid phase film forming method.
【請求項3】 Si単結晶ウェーハの鏡面とは反対側の
裏面に請求項1又は2に記載した方法によって無機質膜
を設け、次いでサンドブラスト法により該ウェーハの裏
面に歪層を導入することを特徴とする半導体基板の製造
方法。
3. An inorganic film is provided on the back surface of the Si single crystal wafer opposite to the mirror surface by the method according to claim 1 or 2, and then a strained layer is introduced on the back surface of the wafer by sandblasting. And a method for manufacturing a semiconductor substrate.
【請求項4】 半導体ウェーハの鏡面とは反対側の裏面
に無機質膜を設け、その表面上をサンドブラストするこ
とによって該半導体ウェーハの裏面に歪層を導入した
後、上記酸化膜を除去することを特徴とする請求項3記
載の半導体基板の製造方法。
4. An inorganic film is provided on the back surface of the semiconductor wafer opposite to the mirror surface, and a strain layer is introduced on the back surface of the semiconductor wafer by sandblasting the surface, and then the oxide film is removed. The method of manufacturing a semiconductor substrate according to claim 3, wherein the semiconductor substrate is manufactured.
JP11689192A 1991-07-19 1992-04-08 Semiconductor substrate and method of manufacturing the same Expired - Fee Related JP2820230B2 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
JP11689192A JP2820230B2 (en) 1992-04-08 1992-04-08 Semiconductor substrate and method of manufacturing the same
DE1992627158 DE69227158T2 (en) 1991-07-19 1992-07-08 Extrinsic gettering for a semiconducting substrate
EP19920111576 EP0525455B1 (en) 1991-07-19 1992-07-08 Extrinsic gettering for a semiconductor substrate

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP11689192A JP2820230B2 (en) 1992-04-08 1992-04-08 Semiconductor substrate and method of manufacturing the same

Publications (2)

Publication Number Publication Date
JPH05291264A true JPH05291264A (en) 1993-11-05
JP2820230B2 JP2820230B2 (en) 1998-11-05

Family

ID=14698198

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Country Status (1)

Country Link
JP (1) JP2820230B2 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6547938B1 (en) 1999-03-25 2003-04-15 Canon Kabushiki Kaisha Anodizing apparatus, utilizing a perforated negative electrode

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6547938B1 (en) 1999-03-25 2003-04-15 Canon Kabushiki Kaisha Anodizing apparatus, utilizing a perforated negative electrode
US7014748B2 (en) 1999-03-25 2006-03-21 Canon Kabushiki Kaisha Anodizing method, substrate processing method, and substrate manufacturing method

Also Published As

Publication number Publication date
JP2820230B2 (en) 1998-11-05

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