JPS62256448A - Detection of defect in silicon substrate - Google Patents
Detection of defect in silicon substrateInfo
- Publication number
- JPS62256448A JPS62256448A JP9799786A JP9799786A JPS62256448A JP S62256448 A JPS62256448 A JP S62256448A JP 9799786 A JP9799786 A JP 9799786A JP 9799786 A JP9799786 A JP 9799786A JP S62256448 A JPS62256448 A JP S62256448A
- Authority
- JP
- Japan
- Prior art keywords
- oxide film
- silicon substrate
- size
- defective
- voltage
- 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
- 229910052710 silicon Inorganic materials 0.000 title claims abstract description 48
- 239000010703 silicon Substances 0.000 title claims abstract description 48
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 title claims abstract description 47
- 239000000758 substrate Substances 0.000 title claims abstract description 46
- 230000007547 defect Effects 0.000 title claims description 46
- 238000001514 detection method Methods 0.000 title 1
- 230000015556 catabolic process Effects 0.000 claims abstract description 25
- 238000000034 method Methods 0.000 claims abstract description 17
- 238000009826 distribution Methods 0.000 claims abstract description 14
- 239000002244 precipitate Substances 0.000 claims description 39
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 13
- 229910052760 oxygen Inorganic materials 0.000 claims description 13
- 239000001301 oxygen Substances 0.000 claims description 13
- 230000002950 deficient Effects 0.000 abstract description 13
- 239000003990 capacitor Substances 0.000 abstract description 4
- 238000010586 diagram Methods 0.000 description 11
- 238000005530 etching Methods 0.000 description 8
- 239000013078 crystal Substances 0.000 description 6
- 239000004065 semiconductor Substances 0.000 description 4
- 235000012431 wafers Nutrition 0.000 description 4
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- 229910052814 silicon oxide Inorganic materials 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 239000002253 acid Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 229910001385 heavy metal Inorganic materials 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 239000012212 insulator Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 150000003376 silicon Chemical class 0.000 description 1
Landscapes
- Testing Or Measuring Of Semiconductors Or The Like (AREA)
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は、シリコン基板（シリコンウェハ）中に含まれ
る酸素析出物の大きさと密度を評価する方法に関するも
のである。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for evaluating the size and density of oxygen precipitates contained in a silicon substrate (silicon wafer).
なお、ここで、酸素析出物とは酸素析出核をも含むもの
として用いる。Note that the term "oxygen precipitates" is used herein to include oxygen precipitate nuclei.
（従来の技術）
半導体素子に用いられるシリコン基板の物性、特にシリ
コン結晶中の欠１ｖｉ（ａ素、炭素、重金属及びそれら
の凝集物、更に、結晶のヒズミ等を総称して、微小欠陥
又は結晶欠陥と呼ばれている）は、半導体素子を製造す
る上で悪影響を及ぼす。(Prior art) The physical properties of silicon substrates used in semiconductor devices, especially defects in silicon crystals (a-elements, carbon, heavy metals, aggregates thereof, crystal distortions, etc., collectively referred to as micro defects or crystal defects) defects (also called defects) have a negative impact on the manufacturing of semiconductor devices.
例えば、シリコン基板が製造プロセス中の熱処理により
そりを生じたり、ＰＮ接合や空乏層などでのリーク電流
の増大、又は、基板のシリコンを直接熱酸化して形成す
るゲート酸化膜欠陥等の原因はシリコン基板の微小欠陥
にある。そのため、この微小欠陥は、シリコン結晶の成
長時に混入する酸素、炭素、金属不純物、結晶のひずみ
等により、プロセス中の熱処理により酸素の析出が生じ
、酸素析出物を形成し、続いて転位や積層欠陥等の結晶
のひずみをも引き起こす。よって、シリコン基、板中の
酸素析出物の密度や大小を知ることは、そのシリコン基
板がプロセスの熱処理によって、ゲート酸化膜欠陥等が
どのような大きさや密度に成長するかを予想できて有効
である。しかしながら、酸素析出物は非常に小さく現在
のところ直接観察することは困難である。For example, causes such as warping of a silicon substrate due to heat treatment during the manufacturing process, increased leakage current at PN junctions or depletion layers, or defects in the gate oxide film formed by direct thermal oxidation of the silicon of the substrate, etc. It is found in minute defects in silicon substrates. Therefore, these micro defects are caused by oxygen, carbon, metal impurities, crystal distortion, etc. mixed in during the growth of silicon crystals, which causes oxygen to precipitate due to heat treatment during the process, forming oxygen precipitates, and subsequently causing dislocations and stacking. It also causes crystal distortion such as defects. Therefore, knowing the density and size of oxygen precipitates in silicon substrates and plates is effective in predicting the size and density of gate oxide film defects, etc. that will grow when the silicon substrate undergoes heat treatment during the process. It is. However, oxygen precipitates are very small and currently difficult to directly observe.
そこで、従来採用されてきた方法というのは、■、＾ｂ
ｅ、 ｅｔ＋ａ１．＋ｌＥＤＭ ａｓ Ｔｅ、ｃｈｎｉ
ｃａｌ Ｄｉｇｅｓｔ、Ｐ、３７２（１９８５）に記載
され、第７図に示されるように、球状の析出物（以下、
単に析出物という）２が分布しているシリコン基板ｌを
熱酸化することによって、第８図に示されるように、シ
リコン酸化膜３を成長させる。この時、シリコン基板１
に存在していた析出物２はシリコン酸化膜（以下、単に
酸化膜という）３内部に取り込まれ、析出物２が酸化膜
欠陥４となる。このような試料を１０枚前後準備する。Therefore, the methods that have been conventionally adopted are ■, ^b
e, et+a1. +lEDM as Te, chni
cal Digest, P, 372 (1985) and shown in FIG. 7, spherical precipitates (hereinafter referred to as
By thermally oxidizing the silicon substrate 1 on which precipitates 2 are distributed, a silicon oxide film 3 is grown as shown in FIG. At this time, silicon substrate 1
The precipitates 2 existing in the silicon oxide film (hereinafter simply referred to as oxide film) 3 are taken into the inside of the silicon oxide film 3, and the precipitates 2 become oxide film defects 4. Prepare approximately 10 such samples.
その後、希釈したＨＦ（フン酸）溶液で、酸化膜３をエ
ツチングする。この時、少なくとも１００人の酸化膜が
残る程度にエツチングする量を各試料について配分する
。つまり、初期の酸化膜の膜厚が４００人であれば、エ
ツチング量は各試料についてθ人、 ３０．６０．・・
・２７０人とする。Thereafter, the oxide film 3 is etched with a diluted HF (hydric acid) solution. At this time, the etching amount is distributed to each sample so that at least 100 oxide films remain. In other words, if the initial oxide film thickness is 400 mm, the etching amount for each sample is θ mm, 30.60 mm.・・・
・The number of people will be 270.
以上の処理により、酸化膜欠陥部分は第９図に示される
ように、局所的にエツチングされ、エツチングされた部
分が酸化膜３を完全に貫くと、そこはピンホール５とな
り、電極形成後電気的には初期短絡となる。As a result of the above processing, the defective part of the oxide film is locally etched as shown in FIG. This results in an initial short circuit.
そして、この初期短絡の生じる量、即ち、ピンホール欠
陥密度ｐ （／ｃｊ）とＨＦ溶液による酸化膜のエツチ
ング量ｘ１の間には、
ｐ −Ｎ ｘ （（２Ｘ −Ｔｏｗ ）／２．２ ＋
Ｌ）−（１）なる関係がある。The amount by which this initial short circuit occurs, that is, between the pinhole defect density p (/cj) and the etching amount x1 of the oxide film by the HF solution is p - N x ((2X - Tow )/2.2 +
There is a relationship L)-(1).
ここで、Ｌはシリコン基板中に含まれる析出物の径、つ
まり、その大きさく口）、Ｔ（Ｉｍは初期の酸化により
形成された酸化膜の膜厚（ａｌ）、Ｎはシリコン基板中
に含まれる析出物の密度（／−）である、なお、上記（
１）式における２、２は析出物２に対する酸化膜欠陥４
の膨張割合を示す。Here, L is the diameter of the precipitate contained in the silicon substrate, that is, its size, T (Im is the thickness (al) of the oxide film formed by initial oxidation, and N is the diameter of the precipitate contained in the silicon substrate. It is the density (/-) of the included precipitates, and the above (
1) In the formula, 2 and 2 are oxide film defects 4 for precipitates 2
It shows the expansion rate of.
そこで、第１０図に示されるように、ＣＺ法によったシ
リコン基板上へ酸化膜を形成し、その膜厚が４０５人の
場合、実験で得られたピンホール欠陥密度ρとエツチン
グ量Ｘを、これらの関係を示す上記式（１）に代入して
析出物の密度Ｎ及び析出物の大きさＬを求める。Therefore, as shown in Fig. 10, when an oxide film is formed on a silicon substrate by the CZ method and the film thickness is 405, the pinhole defect density ρ and the etching amount X obtained in the experiment are , the density N of the precipitates and the size L of the precipitates are determined by substituting them into the above equation (1) showing these relationships.
すると、Ｎ−８，９ｘｌＯ’ （／ｃ＋Ｊ） 、
Ｌ−３２０Ｃ人〕と求められる。Then, N-8,9xlO' (/c+J),
L-320C person] is required.
（発明が解決しようとする問題点）
しかし、以上述べた方法によると、１０枚程度以上の試
料を必要とすること、酸化膜のエツチングを一枚づつ行
う必要があること、ＨＦ系によるエツチングであるため
、酸化膜の欠陥部分と酸化膜部分のエツチング比がエツ
チング溶液の濃度や種類によってかなり変化するため、
上記（１）式から大きくずれる場合があり、得られた析
出物の大きさや密度の値の信顛性が低いという問題があ
った。(Problems to be Solved by the Invention) However, the method described above requires about 10 or more samples, it is necessary to etch the oxide film one by one, and etching using an HF system is difficult. Therefore, the etching ratio between the defective part of the oxide film and the part of the oxide film varies considerably depending on the concentration and type of etching solution.
There was a problem that there was a large deviation from the above formula (1), and the reliability of the size and density values of the obtained precipitates was low.
本発明は、以上述べた試料製作の？ｊＩ雑さを簡略化で
きると共に、使用するウェハを減らすことができ、析出
物の大きさや密度をより正確に、しかも１枚のシリコン
基板を用いて求めることができ、析出物の径の平均では
なく、ばらつきの程度をも評価できるシリコン基板の欠
陥の検出方法を提供することを目的とする。The present invention is directed to the sample preparation described above. In addition to simplifying the complexity, it is possible to reduce the number of wafers used, and the size and density of precipitates can be determined more accurately using a single silicon substrate. It is an object of the present invention to provide a method for detecting defects in a silicon substrate that can evaluate the degree of variation.
（問題点を解決するための手段）
本発明は、上記問題点を解決するために、シリコン基板
中に含まれる析出物の大きさと密度を検出する方法にお
いて、そのシリコン基板を熱酸化し析出物を内部に取り
込んだ酸化膜を形成し、この酸化膜に電極を形成してＭ
ＯＳキャパシタとし、その絶縁耐圧を測定し、その耐圧
分布からシリコン基板中の析出物の大きさと密度を求め
るようにしたものである。(Means for Solving the Problems) In order to solve the above problems, the present invention provides a method for detecting the size and density of precipitates contained in a silicon substrate. Form an oxide film that incorporates M
The dielectric breakdown voltage of the OS capacitor is measured, and the size and density of precipitates in the silicon substrate are determined from the breakdown voltage distribution.
（作用）
本発明によれば、シリコン基板を熱酸化し析出物を内部
に取り込んだ酸化膜を形成し、この酸化膜に電極を形成
してＭＯＳキャパシタとし、その絶縁耐圧を測定し、そ
の耐圧分布からシリコン基板中の析出物の大きさと密度
を求めるようにしたので、シリコン基板内の酸化析出物
の大きさと密度を容易に、しかも正確に検出できる。よ
って、シリコン基板上に形成される半導体装置の歩留ま
り、信頼性の向上を図ることができる。(Function) According to the present invention, a silicon substrate is thermally oxidized to form an oxide film containing precipitates, an electrode is formed on this oxide film to form a MOS capacitor, and its dielectric strength is measured. Since the size and density of the precipitates in the silicon substrate are determined from the distribution, the size and density of the oxidized precipitates in the silicon substrate can be detected easily and accurately. Therefore, it is possible to improve the yield and reliability of semiconductor devices formed on silicon substrates.
（実施例）
以下、本発明の実施例について図面を参照しながら詳細
に説明する。(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.
第３図はチョコラルスキー法（ＣＺ法）によって育成し
たシリコン基板１１を鏡面研摩した時の析出核１２の分
布状態を示す。析出物の径、つまり、析出物の大きさは
Ｌ（Ｃ１１）、密度はＮ （／ｃｊ）とし、この析出物
の大きさＬと密度Ｎを求める方法について説明する。FIG. 3 shows the distribution of precipitated nuclei 12 when a silicon substrate 11 grown by the Czochralski method (CZ method) is mirror-polished. Assuming that the diameter of the precipitate, that is, the size of the precipitate is L (C11) and the density is N (/cj), a method for determining the size L and density N of the precipitate will be explained.
このシリコン基板（Ｐ基板）１１を１０００℃ドライ酸
素雰囲気中で熱酸化し、４００人の酸化膜１３を形成す
る。この場合に、第４図に示されるように、析出物が完
全に酸化膜Ｉ３内に取り込まれた、酸化膜欠陥１４が形
成するように厚い膜が必要である。This silicon substrate (P substrate) 11 is thermally oxidized at 1000° C. in a dry oxygen atmosphere to form a 400-layer oxide film 13. In this case, as shown in FIG. 4, a thick film is required so that the precipitates are completely incorporated into the oxide film I3 and oxide film defects 14 are formed.
この欠陥の大きさをＬＯＩ＋とする。The size of this defect is defined as LOI+.
この完全に取り込まれた酸化膜欠陥１４が酸化膜１３中
に含まれる量、即ち、欠陥密度ρ（個／ａＪ）は、
ρ−Ｎ ｘ （（ＴＯＸ／２．２） −Ｌ）−（２）で
ある。The amount of completely incorporated oxide film defects 14 contained in the oxide film 13, that is, the defect density ρ (pieces/aJ) is ρ−N x ((TOX/2.2) −L)−(2 ).
ここで、この欠陥による耐圧不良の発生機構を説明する
。Here, the mechanism of occurrence of breakdown voltage failure due to this defect will be explained.
第１図は酸化膜欠陥１４を含む酸化膜１３に電極１７を
形成し、シリコン基板１１と電極１７間に電圧ｖ９を印
加した場合を示したものである。酸化膜欠陥１４を通る
Ａ−Ａ ’上での電位分布は第２図のようになる。つま
り、酸化膜欠陥１４の欠陥部分は絶縁性に乏しく絶縁物
というより、むしろ、抵抗体と見なすことができ、上下
方向を酸化膜ではさまれている限りにおいては電流は殆
ど流れず、その結果、この欠陥部分での電圧降下は生じ
ない。結局、すべての電圧■、は、酸化膜の膜厚Ｔ。、
ｌから欠陥部分Ｌ６１１を引いた膜厚、つまり、Ｘｌ＋
に２に分配されて印加される。ここで、欠陥を含む酸化
膜が絶縁破壊を起こすのは、Ｘｌ＋Ｘ！に印加される電
圧が真性な（欠陥を含まない）酸化膜自身がもつ最大破
壊電圧強度を越えた時に生じるものである。FIG. 1 shows a case where an electrode 17 is formed on an oxide film 13 including an oxide film defect 14, and a voltage v9 is applied between the silicon substrate 11 and the electrode 17. The potential distribution on A-A' passing through the oxide film defect 14 is as shown in FIG. In other words, the defective part of the oxide film defect 14 has poor insulation properties and can be regarded as a resistor rather than an insulator, and as long as it is sandwiched between the oxide films in the vertical direction, almost no current flows, and as a result, , no voltage drop occurs at this defective part. After all, all voltages , , are the thickness T of the oxide film. ,
The film thickness obtained by subtracting the defective portion L611 from l, that is, Xl+
It is divided into two parts and applied. Here, the reason why the oxide film containing defects causes dielectric breakdown is Xl+X! This occurs when the voltage applied to the oxide film exceeds the maximum breakdown voltage strength of the intrinsic (defect-free) oxide film itself.
この最大絶縁破壊電圧強度は第５図に実線で示される。This maximum dielectric breakdown voltage strength is shown by the solid line in FIG.
以上のことから、酸化膜の耐圧分布における耐圧不良分
布、つまり、第６図に示される斜線の部分から酸化膜１
４の欠陥の大きさを見積もることができる。ここで、第
６図に示される斜線の部分より高い耐圧を示すものは、
第４図における酸化膜欠陥１５又は１６によるものであ
る。第１０図は酸化膜の初期膜厚が４００人の場合であ
り、斜線部分の最小の電圧Ｖ Ｆ （ｗｉｎ）はＩＩＶ
であり、第５図より、絶縁破壊電圧が１１■の時の酸化
膜の膜厚は５０人である。この膜厚５０人が先に述べた
ｘｌ＋ｘ！に対応する。From the above, the breakdown voltage failure distribution in the breakdown voltage distribution of the oxide film, that is, the oxide film 1
It is possible to estimate the size of 4 defects. Here, those exhibiting a higher withstand voltage than the shaded area shown in Figure 6 are:
This is due to the oxide film defect 15 or 16 in FIG. Figure 10 shows the case where the initial thickness of the oxide film is 400, and the minimum voltage V F (win) in the shaded area is IIV
According to FIG. 5, the thickness of the oxide film is 50 mm when the dielectric breakdown voltage is 11 cm. This film thickness 50 people mentioned earlier xl+x! corresponds to
よって、酸化膜中に含まれる欠陥の大きさは、Ｌ６Ｘ＝
ＴＯＸ （ＸＩ ＋ ｘｔ ） −４００
人−５０人＝３５０人
として求めることができる。Therefore, the size of defects contained in the oxide film is L6X=
TOX (XI + xt) -400
It can be calculated as 350 people - 50 people.
また、第６図に示されるように斜線部分の最大の電圧Ｖ
Ｆ （ＩＩｌａｘ）は２２Ｖであり、この２２Ｖに対
するｘｌ＋ｘ、は第５図より １９０人である。Also, as shown in FIG. 6, the maximum voltage V in the shaded area
F (IIlax) is 22V, and xl+x for this 22V is 190 people from Figure 5.
従って、この場合における酸化膜中に含まれる欠陥の大
きさは、
Ｌａｘ＝ Ｔｏｌｌ （ＸＩ ＋ ｘｔ ）
＝ ４００人−１９０八は２１Ｏ人
として求めることができる。Therefore, the size of the defect included in the oxide film in this case is: Lax= Toll (XI + xt)
= 400 people - 1908 can be calculated as 210 people.
この耐圧分布の斜線の部分は酸化膜欠陥１４が酸化膜１
３中に完全に取り込まれた欠陥によるものである。よっ
て、厚い酸化膜を形成する程、この形の酸化膜欠陥が相
対的に多くなり、耐圧分布において明瞭な分布を示すよ
うになる。つまり、より正確に酸化膜欠陥の大きさを求
めることができる。In the diagonally shaded part of this breakdown voltage distribution, the oxide film defect 14 is the oxide film 1.
This is due to a defect completely incorporated into 3. Therefore, as the oxide film becomes thicker, the number of oxide film defects of this type increases relatively, and the breakdown voltage distribution shows a clear distribution. In other words, the size of the oxide film defect can be determined more accurately.
このようにして求めた２１０人〜３５０人の酸化膜欠陥
の大きさより、酸化膜のシリコン基板中の析出物の径の
大きさは２．２で割ることにより９５人〜１６０人と見
積もることができる。From the size of the oxide film defects obtained in this way for 210 to 350 people, the diameter of the precipitates in the silicon substrate of the oxide film can be estimated to be 95 to 160 people by dividing by 2.2. can.
また、欠陥はウェハ内でランダム分布していることから
一般に、酸化膜欠陥密度ρと耐圧不良率Ｐの間には、
ｐ−（−（１／Ｓ）ｍｉｎ （１−Ｐ）） ・＝（３）
の関係がある。ここでＳはゲート面積、ｆｎは自然対数
である。In addition, since defects are randomly distributed within the wafer, the relationship between the oxide film defect density ρ and the breakdown voltage failure rate P is generally p-(-(1/S)min (1-P)) ・=( 3)
There is a relationship between Here, S is the gate area and fn is the natural logarithm.
上記（２）式と（３）式より、
Ｎ＝ −１ｎ（１−’Ｐ） ／ （Ｓ Ｘ（Ｔｏｗ／２
．２− Ｌ） ）第１Ｏ図における斜線部分の不良率Ｐ
は０．４５であり、Ｓは０．１ｃｍ”、Ｔ、、は４００
ＸＩＯ−’ｃｓ＋、Ｌは耐圧分布の斜線部分の平均値か
ら１３０Ｘ１０−’ａｍの値を採用すると、Ｎは１．１
５ Ｘ １０’個／ｄと求められる。From the above equations (2) and (3), N= -1n(1-'P) / (S X(Tow/2
．． 2-L)) Defective rate P in the shaded area in Figure 1O
is 0.45, S is 0.1 cm", T is 400
XIO-'cs+, L adopts the value of 130X10-'am from the average value of the shaded part of the breakdown voltage distribution, then N is 1.1
It is calculated as 5 x 10' pieces/d.
（発明の効果）
以上、詳細に説明したように、本発明によれば、シリコ
ン基板中に含まれる酸素析出物の大きさと密度を評価す
るシリコン基板の欠陥の検出方法において、そのシリコ
ン基板上に熱酸化膜を形成し、その熱酸化膜上に電極を
形成し、その電極と前記シリコン基板との間に電圧を印
加して前記酸化膜の絶縁破壊特性を測定し、該酸化膜の
耐圧分布に基づいて酸素析出物の大きさと密度を求める
ようにしたので、
（１）従来の方法による試料製作の複雑さを簡略化でき
ると共に、使用するウェハを１枚に減らすことができる
。(Effects of the Invention) As described in detail above, according to the present invention, in a method for detecting defects in a silicon substrate for evaluating the size and density of oxygen precipitates contained in a silicon substrate, A thermal oxide film is formed, an electrode is formed on the thermal oxide film, and a voltage is applied between the electrode and the silicon substrate to measure the dielectric breakdown characteristics of the oxide film, and the breakdown voltage distribution of the oxide film is determined. Since the size and density of oxygen precipitates are determined based on the following: (1) The complexity of sample preparation by conventional methods can be simplified and the number of wafers used can be reduced to one.
（２）析出物の大きさや密度をより正確に、しかも析出
物の径の平均ではなく、ばらつきの程度をも評価できる
。(2) The size and density of precipitates can be evaluated more accurately, and not only the average diameter of the precipitates but also the degree of variation can be evaluated.
このように、シリコン基板内の酸化析出物の大きさと密
度を容易に、しかも正確に検出できるので、シリコン基
板上に形成される酸化膜欠陥をなくすことができ、シリ
コン基板上に形成される半導体装置、特に、ゲート酸化
膜が集積されるＶＬＳｌの歩留まり及び信鎖性の向上に
資するところ大である。In this way, the size and density of oxidized precipitates within a silicon substrate can be easily and accurately detected, making it possible to eliminate oxide film defects formed on a silicon substrate and improve the quality of semiconductors formed on a silicon substrate. This greatly contributes to improving the yield and reliability of devices, especially VLSI devices in which gate oxide films are integrated.
第１図は本発明のシリコン基板の欠陥の検出方法を説明
するための装置の説明図、第２図は第１図のＡ−Ａ ’
線の位置対電位特性図、第３図は本発明のシリコン基板
の説明図、第４図は本発明のシリコン基板と酸化膜の説
明図、第５図は酸化膜の膜厚対絶縁破壊電圧特性図、第
６図は絶縁破壊電圧対絶縁破壊発生回数特性図、第７図
は従来のシリコン基板の説明図、第８図は従来のシリコ
ン基板と酸化膜の説明図、第９図は従来の酸化膜へのピ
ンホール発生の説明図、第１０図は従来の酸化膜のエン
チング膜厚対ピンホール欠陥密度特性図である。
１１・・・シリコン基板、１２・・・析出物、Ｌ・・・
析出物の大きさく析出物の径）、Ｎ・・・析出物の密度
、１３・・・酸化膜、１４・・・酸化膜欠陥、ρ・・・
欠陥密度（面密度）、Ｔｏや・・・初期の酸化膜の膜厚
、１５．１６・・・酸化膜欠陥、１７・・・電極、Ｌａ
Ｉ３・・・欠陥部分、”ＩＩＫ！・・・真性な（欠陥を
含まない）酸化膜の膜厚、Ｐ・・・耐圧不良率、Ｓ・・
・ゲート面積。FIG. 1 is an explanatory diagram of an apparatus for explaining the method of detecting defects in a silicon substrate according to the present invention, and FIG.
Figure 3 is an explanatory diagram of the silicon substrate of the present invention, Figure 4 is an explanatory diagram of the silicon substrate and oxide film of the present invention, and Figure 5 is the diagram of the oxide film thickness versus dielectric breakdown voltage. Characteristic diagram, Figure 6 is a characteristic diagram of dielectric breakdown voltage vs. number of dielectric breakdown occurrences, Figure 7 is an explanatory diagram of a conventional silicon substrate, Figure 8 is an explanatory diagram of a conventional silicon substrate and oxide film, and Figure 9 is an explanatory diagram of a conventional silicon substrate. FIG. 10 is an explanatory diagram of pinhole generation in an oxide film, and FIG. 10 is a characteristic diagram of etching film thickness versus pinhole defect density of a conventional oxide film. 11... Silicon substrate, 12... Precipitate, L...
Precipitate size (precipitate diameter), N... precipitate density, 13... oxide film, 14... oxide film defect, ρ...
Defect density (area density), To... initial oxide film thickness, 15.16... oxide film defect, 17... electrode, La
I3...defect part, "IIK!...thickness of the intrinsic (no defects) oxide film, P...breakdown failure rate, S...
・Gate area.
Claims (1)
を評価する方法において、 （ａ）前記シリコン基板上に熱酸化膜を形成し、 （ｂ）該酸化膜上に電極を形成し、 （ｃ）該電極と前記シリコン基板との間に電圧を印加し
て前記酸化膜の絶縁破壊特性を測定し、 （ｄ）該酸化膜の耐圧分布に基づいて酸素析出物の大き
さと密度を求めるようにしたことを特徴とするシリコン
基板の欠陥の検出方法。[Claims] A method for evaluating the size and density of oxygen precipitates contained in a silicon substrate, comprising: (a) forming a thermal oxide film on the silicon substrate; (b) forming an electrode on the oxide film; (c) measuring the dielectric breakdown characteristics of the oxide film by applying a voltage between the electrode and the silicon substrate; (d) determining the size of oxygen precipitates based on the breakdown voltage distribution of the oxide film; A method for detecting defects in a silicon substrate, characterized in that the density is determined.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9799786A JPS62256448A (en) | 1986-04-30 | 1986-04-30 | Detection of defect in silicon substrate |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9799786A JPS62256448A (en) | 1986-04-30 | 1986-04-30 | Detection of defect in silicon substrate |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS62256448A true JPS62256448A (en) | 1987-11-09 |
Family
ID=14207302
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP9799786A Pending JPS62256448A (en) | 1986-04-30 | 1986-04-30 | Detection of defect in silicon substrate |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS62256448A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2014107374A (en) * | 2012-11-27 | 2014-06-09 | Sumco Corp | Semiconductor sample, electric evaluation methods, and evaluation device |
-
1986
- 1986-04-30 JP JP9799786A patent/JPS62256448A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2014107374A (en) * | 2012-11-27 | 2014-06-09 | Sumco Corp | Semiconductor sample, electric evaluation methods, and evaluation device |
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