JP2002184828A - Method of analyzing metallic impurities in semiconductor substrate - Google Patents
Method of analyzing metallic impurities in semiconductor substrateInfo
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- JP2002184828A JP2002184828A JP2000385395A JP2000385395A JP2002184828A JP 2002184828 A JP2002184828 A JP 2002184828A JP 2000385395 A JP2000385395 A JP 2000385395A JP 2000385395 A JP2000385395 A JP 2000385395A JP 2002184828 A JP2002184828 A JP 2002184828A
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- semiconductor substrate
- analysis
- decomposition solution
- metal impurities
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、飛行時間型二次イ
オン質量分析法による、半導体基板中または半導体基板
表面に含まれる金属不純物の分析方法に関する。The present invention relates to a method of analyzing metal impurities contained in or on a semiconductor substrate by time-of-flight secondary ion mass spectrometry.
【０００２】[0002]
【従来の技術】半導体デバイスの高集積化・高性能化に
伴い、絶縁膜や半導体膜層に微量のＮａ、Ａｌ、Ｆｅ、
Ｃｕ等の金属不純物が含まれても、酸化膜耐圧不良やリ
ーク電流の増大等、素子に致命的な影響を及ぼし、製品
歩留まりを大きく左右する状況になっている。このた
め、製造工程の清浄度管理が非常に重要であり、清浄度
管理に用いる金属不純物の分析法には、１０7〜１０8at
oms/cm2レベルの検出感度が要求される。また、各種の
金属不純物が半導体デバイスに影響を及ぼすため、各種
の元素を分析する必要があり、各元素ごとの分析では、
分析に多くの時間を要するので、多元素を同時に分析で
きることも要求されている。2. Description of the Related Art As semiconductor devices become more highly integrated and more sophisticated, trace amounts of Na, Al, Fe,
Even if a metal impurity such as Cu is contained, it has a fatal effect on the device such as an oxide film withstanding voltage failure and an increase in leak current, and the product yield is largely influenced. For this reason, cleanliness control in the manufacturing process is very important, and the method of analyzing metal impurities used for cleanliness control is 10 7 to 10 8 at.
oms / cm 2 level detection sensitivity is required. Also, since various metal impurities affect the semiconductor device, it is necessary to analyze various elements, and in the analysis for each element,
Since much time is required for analysis, it is also required that multiple elements can be analyzed simultaneously.
【０００３】現在、半導体基板中および半導体基板表面
に含まれる超微量の金属不純物を分析する各種の方法が
提案されており、中でも特開平９−２６４０１号公報に
は、多元素を同時に高感度で分析する方法が開示されて
いる。この特開平９−２６４０１号公報に開示されてい
る方法は、半導体薄膜および半導体基板を分解液により
分解した後、分析用基板上で前記分解液を気化させて、
半導体基板薄膜および基板の不純物を濃縮乾固し、この
濃縮乾固された不純物を全反射蛍光Ｘ線分光分析法（To
tal Reflection X-ray Fluorescence Spectrometry ,
（ＴＲＥＸ））により分析するものである。At present, various methods have been proposed for analyzing ultra-trace amounts of metal impurities contained in a semiconductor substrate and on the surface of a semiconductor substrate. Among them, Japanese Patent Application Laid-Open No. 9-26401 discloses a method for simultaneously analyzing multiple elements with high sensitivity. A method for analyzing is disclosed. In the method disclosed in Japanese Patent Application Laid-Open No. 9-26401, after a semiconductor thin film and a semiconductor substrate are decomposed with a decomposition solution, the decomposition solution is vaporized on a substrate for analysis,
The impurities in the semiconductor substrate thin film and the substrate are concentrated and dried, and the concentrated and dried impurities are analyzed by total reflection X-ray fluorescence spectroscopy (To
tal Reflection X-ray Fluorescence Spectrometry,
(TREX)).
【０００４】[0004]
【発明が解決しようとする課題】前記従来のＴＲＥＸに
よる半導体基板中および半導体基板表面に含まれる金属
不純物を分析する方法では、検出感度が１０10atoms/cm
2レベルと、現在、半導体デバイスの清浄度管理に用い
られる金属不純物の分析に要求される検出感度レベルの
１０7〜１０8atoms/cm2より低いという問題があった。
また、ＴＲＥＸでは、分析用基板としてシリコン基板を
用いた場合、ＮａやＡｌなどの金属が分析できず、Ｎａ
やＡｌなどの金属を分析するには、分析用基板にアモル
ファスカーボン基板を用いる必要があり、分析する金属
により、分析用基板を使い分けなければならないという
問題があった。In the conventional method for analyzing metal impurities contained in a semiconductor substrate and on the surface of a semiconductor substrate by TREX, the detection sensitivity is 10 10 atoms / cm 2.
And 2 levels, currently, there is a problem that less than 10 7 ~10 8 atoms / cm 2 of the detection sensitivity level required for the analysis of metal impurities used for cleanliness management of semiconductor devices.
Further, in TREX, when a silicon substrate is used as a substrate for analysis, metals such as Na and Al cannot be analyzed.
In order to analyze metals such as Al and Al, it is necessary to use an amorphous carbon substrate as the analysis substrate, and there is a problem that the analysis substrate must be used properly depending on the metal to be analyzed.
【０００５】[0005]
【課題を解決するための手段】本発明の第１の半導体基
板の金属不純物の分析方法は、半導体基板に含まれない
成分を内標準物質として添加した分解液により半導体基
板を処理する工程と、前記半導体基板を処理した分解液
を分析用基板上で乾固する工程と、前記分析用基板上で
乾固した成分を飛行時間型二次イオン質量分析装置によ
り分析する工程とを備えたことである。According to the first method of the present invention for analyzing metal impurities in a semiconductor substrate, a semiconductor substrate is treated with a decomposition solution to which a component not contained in the semiconductor substrate is added as an internal standard substance; A step of drying the decomposition solution obtained by treating the semiconductor substrate on an analysis substrate, and a step of analyzing the components dried on the analysis substrate by a time-of-flight secondary ion mass spectrometer. is there.
【０００６】本発明の第２の半導体基板の金属不純物の
分析方法は、第１の半導体基板の金属不純物の分析方法
において、分解液に添加する内標準物質が、イットリウ
ム、ロジウム、ツリウムまたはルテチウムであることで
ある。According to a second method for analyzing metal impurities in a semiconductor substrate of the present invention, in the first method for analyzing metal impurities in a semiconductor substrate, the internal standard substance added to the decomposition solution is yttrium, rhodium, thulium or lutetium. That is.
【０００７】本発明の第３の半導体基板の金属不純物の
分析方法は、第１または２の半導体基板の金属不純物の
分析方法において、分解液が、フッ酸、硝酸、塩酸、過
酸化水素、硫酸およびアンモニアの少なくとも１種類の
水溶液からなることである。A third method for analyzing metal impurities in a semiconductor substrate according to the present invention is the method for analyzing metal impurities in the first or second semiconductor substrate, wherein the decomposition solution is hydrofluoric acid, nitric acid, hydrochloric acid, hydrogen peroxide or sulfuric acid. And at least one aqueous solution of ammonia.
【０００８】本発明の第４の半導体基板の金属不純物の
分析方法は、第１ないし３のいずれかの半導体基板の金
属不純物の分析方法において、分析用基板が、シリコン
基板であることである。According to a fourth method for analyzing metal impurities in a semiconductor substrate of the present invention, in the method for analyzing metal impurities in any of the first to third semiconductor substrates, the analysis substrate is a silicon substrate.
【０００９】[0009]
【発明の実施の形態】実施の形態１．図１は、本発明の
実施の形態１に係る半導体基板中または半導体基板表面
に含まれる金属不純物の分析方法を模式的に示す工程図
である。図１において、１は分解液、１ａは内標準物質
を添加した分解液、２は内標準物質、３はテフロン（登
録商標）容器、４，４ａはマイクロシリンジ、５は半導
体基板、６はテフロン皿、７は分析用基板、８は乾固
物、９は加熱手段、１０は飛行時間型二次イオン質量分
析装置（ＴＯＦ−ＳＩＭＳ装置）、１１は検量線であ
る。DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a process chart schematically showing a method for analyzing metal impurities contained in a semiconductor substrate or on a semiconductor substrate surface according to the first embodiment of the present invention. In FIG. 1, 1 is a decomposition solution, 1a is a decomposition solution to which an internal standard substance is added, 2 is an internal standard substance, 3 is a Teflon (registered trademark) container, 4, 4a is a micro syringe, 5 is a semiconductor substrate, 6 is Teflon. A plate, 7 is a substrate for analysis, 8 is a dried product, 9 is a heating means, 10 is a time-of-flight secondary ion mass spectrometer (TOF-SIMS device), and 11 is a calibration curve.
【００１０】まず、図１に示す第１の工程では、テフロ
ン容器３に採取した分解液１に、内標準物質２として、
１０〜１００ppbの半導体基板５中に不純物として含ま
れない成分を添加する。内標準物質２としては、例え
ば、イットリウム（Ｙ）、ロジウム（Ｒｈ）、ツリウム
（Ｔｍ）またはルテチウム（Ｌｕ）があげられる。分解
液１としては、フッ酸、硝酸、塩酸、過酸化水素、硫酸
およびアンモニアの単体あるいは混合の水溶液が用いら
れる。半導体基板５表面に含まれる金属不純物を分析す
る場合、分解液１としては、例えば、０．０５〜６．０
重量％のフッ酸、過酸化水素、塩酸、硫酸またはアンモ
ニアの単独または混合の水溶液が用いられる。また、半
導体基板５中の金属不純物を分析する場合は、分解液１
としては、例えば、０．０１〜１０重量％のフッ酸と２
５〜６８重量％の硝酸との混合水溶液が用いられる。First, in the first step shown in FIG. 1, a decomposition solution 1 collected in a Teflon container 3
A component not included as an impurity in the semiconductor substrate 5 of 10 to 100 ppb is added. Examples of the internal standard substance 2 include yttrium (Y), rhodium (Rh), thulium (Tm), and lutetium (Lu). As the decomposition solution 1, a single or mixed aqueous solution of hydrofluoric acid, nitric acid, hydrochloric acid, hydrogen peroxide, sulfuric acid, and ammonia is used. When metal impurities contained in the surface of the semiconductor substrate 5 are analyzed, the decomposition solution 1 is, for example, 0.05 to 6.0.
A single or mixed aqueous solution of hydrofluoric acid, hydrogen peroxide, hydrochloric acid, sulfuric acid or ammonia in% by weight is used. When analyzing metal impurities in the semiconductor substrate 5, the decomposition solution 1
For example, 0.01 to 10% by weight of hydrofluoric acid and 2
A mixed aqueous solution with 5-68% by weight of nitric acid is used.
【００１１】次に、図１に示す第２の工程では、第１の
工程で内標準物質２を添加した分解液１ａを用いて、半
導体基板５中の不純物を分解溶解させて回収する。半導
体基板５表面に含まれる金属不純物の分析では、第２の
工程のａに示すように、半導体基板５表面にマイクロシ
リンジ４を用い５０〜１５０μｌの分解液１ａを滴下
し、次いで走査し、半導体基板５表面上の金属不純物を
分解溶解させる。半導体基板５中の金属不純物を分析す
るには、第２の工程のｂに示すように、５〜１５ｍｌの
分解液１ａをテフロン皿６に採取し、この分解液１ａに
半導体基板５を浸漬し溶解する。Next, in a second step shown in FIG. 1, the impurities in the semiconductor substrate 5 are decomposed and dissolved and recovered using the decomposition solution 1a to which the internal standard substance 2 has been added in the first step. In the analysis of metal impurities contained in the surface of the semiconductor substrate 5, as shown in a of the second step, 50 to 150 μl of the decomposition solution 1 a is dropped on the surface of the semiconductor substrate 5 using the micro syringe 4, and then the semiconductor is scanned. The metal impurities on the surface of the substrate 5 are decomposed and dissolved. To analyze metal impurities in the semiconductor substrate 5, as shown in b of the second step, 5 to 15 ml of the decomposition solution 1a is collected in a Teflon dish 6, and the semiconductor substrate 5 is immersed in the decomposition solution 1a. Dissolve.
【００１２】次に、図１に示す第３の工程では、第２の
工程のａの処理をした半導体基板５上の分解液１ａ、ま
たは、第２の工程のｂの処理をしたテフロン皿の所定量
の分解液１ａを、マイクロシリンジ４ａで採取し、分析
用基板７に移動させる。加熱手段９により分析用基板７
上の分解液１ａを加熱、乾固させ、不純物を含有した乾
固物８を得る。本実施の形態では、分析用基板７とし
て、予めフッ酸および過酸化水素水で表面を清浄化した
シリコン基板の小片を用いる。分解液１ａを乾固させる
加熱温度としては、９０〜１５０℃程度が好ましい。Next, in the third step shown in FIG. 1, the decomposition solution 1a on the semiconductor substrate 5 which has been subjected to the processing of the second step a or the Teflon dish which has been subjected to the processing of the second step b is prepared. A predetermined amount of the decomposition solution 1a is collected by the micro syringe 4a and moved to the analysis substrate 7. Analysis substrate 7 by heating means 9
The above decomposition solution 1a is heated and dried to obtain a dried product 8 containing impurities. In the present embodiment, a small piece of a silicon substrate whose surface has been previously cleaned with hydrofluoric acid and hydrogen peroxide solution is used as the analysis substrate 7. The heating temperature for drying the decomposition solution 1a is preferably about 90 to 150 ° C.
【００１３】次に、図１に示す第４の工程では、第３の
工程で分析用基板７上に得られた不純物を含む乾固物８
を飛行時間型二次イオン質量分析装置（ＴＯＦ−ＳＩＭ
Ｓ装置）１０で分析し、金属不純物の二次イオン強度を
得る。それと、得られた各金属不純物の二次イオン強度
を、内標準物質の二次イオン強度で規格化し、各金属不
純物の二次イオン相対強度を算出する。Next, in a fourth step shown in FIG. 1, a dried product 8 containing impurities obtained on the analysis substrate 7 in the third step is formed.
Time-of-flight secondary ion mass spectrometer (TOF-SIM)
(S apparatus) 10 to obtain the secondary ionic strength of metal impurities. Then, the obtained secondary ionic strength of each metal impurity is normalized by the secondary ionic strength of the internal standard substance, and the secondary ion relative strength of each metal impurity is calculated.
【００１４】次に、図１に示す第５の工程では、既知量
の金属と内標準物質２とを添加した分解液の標準試料お
よび内標準物質２のみを添加した分解液のブランク試料
を、第３の工程の処理を行い分析基板上に各々の乾固物
を得る。次に、これら乾固物について第４の工程の処理
を行い、既知濃度の各金属の二次イオン相対強度を求
め、各金属の検量線１１を作成する。そして、この得ら
れた検量線１１を用い、各金属不純物の二次イオン相対
強度から、各金属不純物の濃度を定量する。Next, in a fifth step shown in FIG. 1, a standard sample of the decomposition solution to which a known amount of metal and the internal standard substance 2 are added and a blank sample of the decomposition solution to which only the internal standard substance 2 is added are prepared. The process of the third step is performed to obtain each dried product on the analysis substrate. Next, the dried product is subjected to the process of the fourth step, the secondary ion relative intensity of each metal of a known concentration is determined, and a calibration curve 11 of each metal is created. Then, using the obtained calibration curve 11, the concentration of each metal impurity is quantified from the secondary ion relative intensity of each metal impurity.
【００１５】[0015]
【実施例】実施例１．本発明の効果を検証するため、表
面を洗浄処理し不純物を除去した半導体基板を、既知濃
度の金属不純物を含有する処理液で汚染処理して調製し
た被分析試料についての分析例を示す。第１の工程とし
て、内標準物質２として１０ppbのＲｈを添加した、
１．０重量％フッ酸と１．０重量％過酸化水素とを含有
する水溶液を、分解液１として調製する。第２の工程と
して、内標準物質を含有する分解液１ａの１００μｌ
を、前記被分析試料の半導体基板５上に滴下、走査し、
半導体基板５表面上に存在する金属不純物を分解溶解す
る。第３の工程として、この金属不純物を含有する分解
液１ａをマイクロシリンジ４ａで回収し、表面を清浄化
した分析用シリコン基板７上に滴下する。この分解液１
ａの液滴を載置した分析用シリコン基板７を１２０℃で
加熱し、液滴を蒸発、乾固し、金属不純物を含有する乾
固物８を得る。[Embodiment 1] In order to verify the effects of the present invention, an analysis example of an analyte sample prepared by subjecting a semiconductor substrate whose surface has been cleaned to remove impurities to a contamination treatment with a treatment solution containing a known concentration of metal impurities will be described. As a first step, 10 ppb of Rh was added as an internal standard substance 2,
An aqueous solution containing 1.0% by weight hydrofluoric acid and 1.0% by weight of hydrogen peroxide is prepared as a decomposition solution 1. As a second step, 100 μl of the decomposition solution 1a containing the internal standard substance was used.
Is dropped and scanned on the semiconductor substrate 5 of the sample to be analyzed,
The metal impurities existing on the surface of the semiconductor substrate 5 are decomposed and dissolved. As a third step, the decomposition solution 1a containing the metal impurities is collected by the micro syringe 4a and dropped on the analytical silicon substrate 7 whose surface is cleaned. This decomposition liquid 1
The silicon substrate for analysis 7 on which the droplet a is mounted is heated at 120 ° C., and the droplet is evaporated and dried to obtain a dried product 8 containing metal impurities.
【００１６】第４の工程として、金属不純物を含有する
乾固物８を載置した分析用シリコン基板７を、ＴＯＦ−
ＳＩＭＳの分析装置１０にセットし、金属不純物を分析
する。得られた各金属不純物の二次イオン強度を、内標
準物質であるＲｈの二次イオン強度で規格化し、各金属
不純物の二次イオン相対強度を求める。第５の工程とし
て、予め既知濃度の金属を含有した分解液の標準試料を
用いて求めた二次イオン相対強度と金属濃度との検量線
１１から、各金属不純物の濃度を求め表１に示した。表
１には、金属不純物の代表的なものとして、Ｎａ、Ａ
ｌ、Ｆｅ、ＮｉおよびＣｕを示した。表１から明らかな
ように、多元素が同時に検出でき、しかも、分析用基板
７にシリコン基板を用いてもＮａとＡｌとが分析でき
る。また、内標準物質を用いているので、分析用基板の
表面の影響を除くことができ、バラツキのない測定が可
能になり、半導体デバイスの清浄度管理で要求される１
０7〜１０8atoms/cm2レベルの金属不純物が精度良く検
出できる。As a fourth step, a silicon substrate 7 for analysis on which a dried substance 8 containing metal impurities is placed is placed on a TOF-
It is set in the SIMS analyzer 10 and metal impurities are analyzed. The obtained secondary ionic strength of each metal impurity is normalized by the secondary ionic strength of Rh as the internal standard substance, and the secondary ion relative strength of each metal impurity is obtained. In the fifth step, the concentration of each metal impurity was determined from the calibration curve 11 of the relative intensity of the secondary ion and the metal concentration, which was previously determined using a standard sample of a decomposition solution containing a known concentration of metal, and shown in Table 1. Was. Table 1 shows that Na, A
1, Fe, Ni and Cu are shown. As is clear from Table 1, multiple elements can be detected simultaneously, and Na and Al can be analyzed even when a silicon substrate is used as the analysis substrate 7. Further, since the internal standard is used, the influence of the surface of the substrate for analysis can be eliminated, and measurement without variation can be performed.
0 7 ~10 8 atoms / cm 2 level of metal impurities can be accurately detected.
【００１７】実施例２．〜４．分解液に添加する内標準
物質を実施例１のＲｈに替えて、１０ppbのＹ、Ｔｍま
たはＬｕを用いた以外、実施例１と同様にして、前記被
分析試料である半導体基板表面上の金属不純物を分析し
た。検出されたＮａ、Ａｌ、Ｆｅ、ＮｉおよびＣｕの各
金属濃度レベルを表１に示す。表１から明らかなよう
に、多元素が同時に検出でき、半導体デバイスの清浄度
管理で要求される１０7〜１０8atoms/cm2レベルの金属
不純物が精度良く検出できる。Embodiment 2 FIG. ~ 4. In the same manner as in Example 1 except that 10 ppb of Y, Tm or Lu was used instead of Rh of Example 1 as the internal standard substance added to the decomposition solution, the metal on the surface of the semiconductor substrate as the sample to be analyzed was used. Impurities were analyzed. Table 1 shows the detected metal concentration levels of Na, Al, Fe, Ni and Cu. As is clear from Table 1, multiple elements can be detected at the same time, and metal impurities at the level of 10 7 to 10 8 atoms / cm 2 required for cleanliness control of semiconductor devices can be detected with high accuracy.
【００１８】比較例１．内標準物質を含有しない１重量
％のフッ酸と1重量％の過酸化水素との混合水溶液の分
解液１を用いた以外、実施例１と同様にして、前記被分
析試料である半導体基板表面上の金属不純物を分析し、
その結果を表１に示す。本比較例では、内標準物質を用
いていないので、各金属の二次イオン強度から、各金属
の濃度を求めた。表１から明らかなように、半導体基板
の汚染量に対し分析結果はバラツキが大きく、精度の良
い分析ができなかった。これは、分析用基板の表面の影
響によると考えられる。Comparative Example 1 The surface of the semiconductor substrate which is the sample to be analyzed in the same manner as in Example 1 except that the decomposition solution 1 of a mixed aqueous solution of 1% by weight of hydrofluoric acid and 1% by weight of hydrogen peroxide containing no internal standard substance was used. Analyze the above metal impurities,
Table 1 shows the results. In this comparative example, since no internal standard substance was used, the concentration of each metal was determined from the secondary ionic strength of each metal. As is evident from Table 1, the results of the analysis vary widely with respect to the amount of contamination of the semiconductor substrate, and accurate analysis was not possible. This is considered to be due to the influence of the surface of the analysis substrate.
【００１９】実施例５．〜７．分解液を1重量％のフッ
酸と1重量％の過酸化水素との混合水溶液に替えて、表
２の実施例５〜７に示すものを用いた以外、実施例１と
同様にして、前記被分析試料である半導体基板表面上の
金属不純物を分析した。検出されたＮａ、Ａｌ、Ｆｅ、
ＮｉおよびＣｕの各金属濃度レベルを表２に示す。表２
から明らかなように、多元素が同時に検出でき、半導体
デバイスの清浄度管理で要求される１０7〜１０8atoms/
cm2レベルの金属不純物が精度良く検出できる。Embodiment 5 FIG. ~ 7. The same procedure as in Example 1 was repeated except that the decomposition solution was replaced with a mixed aqueous solution of 1% by weight of hydrofluoric acid and 1% by weight of hydrogen peroxide, and the ones shown in Examples 5 to 7 in Table 2 were used. Metal impurities on the surface of the semiconductor substrate as the sample to be analyzed were analyzed. Na, Al, Fe,
Table 2 shows the respective metal concentration levels of Ni and Cu. Table 2
As can be seen from the above, multiple elements can be detected simultaneously, and 10 7 to 10 8 atoms /
cm 2 level metal impurities can be accurately detected.
【００２０】実施例８．分解液として、1重量％のフッ
酸と1重量％の過酸化水素との混合水溶液に替えて、
０．０５重量％のフッ酸と３５重量％の硝酸との混合水
溶液を用い、前記被分析試料である汚染した半導体基板
を溶解した後、第３の工程として、この金属不純物を含
有する分解液１ａをマイクロシリンジ４ａで所定量採取
し、表面を清浄化した分析用シリコン基板７上に滴下す
る。この分解液１ａの液滴を載置した分析用シリコン基
板７を１４０℃で加熱し、液滴を蒸発、乾固し、金属不
純物を含有する乾固物８を得る。次に、実施例１と同様
の、第４と第５との工程により、半導体基板中の金属不
純物を分析した。検出されたＮａ、Ａｌ、Ｆｅ、Ｎｉお
よびＣｕの各金属濃度レベルを表２に示す。表２から明
らかなように、多元素が同時に検出でき、半導体デバイ
スの清浄度管理で要求される１０7〜１０8atoms/cm2レ
ベルの金属不純物が精度良く検出できる。Embodiment 8 FIG. As a decomposition solution, replace with a mixed aqueous solution of 1% by weight of hydrofluoric acid and 1% by weight of hydrogen peroxide,
Using a mixed aqueous solution of 0.05% by weight of hydrofluoric acid and 35% by weight of nitric acid to dissolve the contaminated semiconductor substrate, which is the sample to be analyzed, as a third step, a decomposition solution containing this metal impurity A predetermined amount of 1a is sampled with a microsyringe 4a and dropped on a silicon substrate 7 for analysis whose surface has been cleaned. The analytical silicon substrate 7 on which the droplets of the decomposition solution 1a are mounted is heated at 140 ° C., and the droplets are evaporated and dried to obtain a dried product 8 containing metal impurities. Next, the metal impurities in the semiconductor substrate were analyzed by the fourth and fifth steps as in Example 1. Table 2 shows the detected metal concentration levels of Na, Al, Fe, Ni and Cu. As is clear from Table 2, multiple elements can be detected at the same time, and metal impurities at the level of 10 7 to 10 8 atoms / cm 2 required for cleanliness control of semiconductor devices can be detected with high accuracy.
【００２１】[0021]
【表１】 [Table 1]
【００２２】[0022]
【表２】 [Table 2]
【００２３】[0023]
【発明の効果】本発明の第１の半導体基板の金属不純物
の分析方法は、半導体基板に含まれない成分を内標準物
質として添加した分解液により半導体基板を処理する工
程と、前記半導体基板を処理した分解液を分析用基板上
で乾固する工程と、前記分析用基板上で乾固した成分を
飛行時間型二次イオン質量分析装置により分析する工程
とを備えたことであり、多元素が同時に検出でき、しか
も、分析用基板にシリコン基板を用いてもＮａとＡｌと
が分析できる。また、分析用基板表面の影響を除くこと
ができるので、バラツキのない測定が可能になり、半導
体デバイスの清浄度管理で要求される１０7〜１０8atom
s/cm2レベルの金属不純物が検出できる。According to the first method for analyzing metal impurities in a semiconductor substrate of the present invention, a step of treating the semiconductor substrate with a decomposition solution to which a component not contained in the semiconductor substrate is added as an internal standard substance; A step of drying the treated decomposition solution on an analysis substrate; anda step of analyzing the components dried on the analysis substrate by a time-of-flight secondary ion mass spectrometer. Can be simultaneously detected, and Na and Al can be analyzed even when a silicon substrate is used as the analysis substrate. In addition, since the influence of the surface of the analysis substrate can be eliminated, measurement without variation can be performed, and 10 7 to 10 8 atoms required for cleanliness control of a semiconductor device can be obtained.
s / cm 2 level metal impurities can be detected.
【００２４】本発明の第２の半導体基板の金属不純物の
分析方法は、第１の半導体基板の金属不純物の分析方法
において、分解液に添加する内標準物質が、イットリウ
ム、ロジウム、ツリウムまたはルテチウムであることで
あり、多元素が同時に検出でき、しかも、分析用基板に
シリコン基板を用いてもＮａとＡｌとが分析できる。ま
た、検量線作成が容易であり、分析用基板表面の影響を
除くことができるので、バラツキのない測定が可能にな
り、半導体デバイスの清浄度管理で要求される１０7〜
１０8atoms/cm2レベルの金属不純物が検出できる。According to a second method for analyzing metal impurities in a semiconductor substrate of the present invention, in the first method for analyzing metal impurities in a semiconductor substrate, the internal standard substance added to the decomposition solution is yttrium, rhodium, thulium or lutetium. That is, multiple elements can be detected simultaneously, and Na and Al can be analyzed even when a silicon substrate is used as the analysis substrate. Further, since a calibration curve can be easily created and the influence of the surface of the analysis substrate can be eliminated, it is possible to perform measurement without variation, and it is necessary to control the cleanliness of the semiconductor device from 10 7 to 10 7 .
A metal impurity of a level of 10 8 atoms / cm 2 can be detected.
【００２５】本発明の第３の半導体基板の金属不純物の
分析方法は、第１または２の半導体基板の金属不純物の
分析方法において、分解液が、フッ酸、硝酸、塩酸、過
酸化水素、硫酸およびアンモニアの少なくとも１種類の
水溶液からなることであり、半導体基板の金属不純物を
容易に溶解回収できる。According to a third method for analyzing metal impurities of a semiconductor substrate according to the present invention, the decomposition solution may be a hydrofluoric acid, a nitric acid, a hydrochloric acid, a hydrogen peroxide or a sulfuric acid. And at least one aqueous solution of ammonia, so that metal impurities in the semiconductor substrate can be easily dissolved and recovered.
【００２６】本発明の第４の半導体基板の金属不純物の
分析方法は、第１ないし３のいずれかの半導体基板の金
属不純物の分析方法において、分析用基板が、シリコン
基板であることであり、分解液の蒸発、乾固が容易で、
飛行時間型二次イオン質量分析方法で、金属不純物を分
析するのに適している。According to a fourth method for analyzing metal impurities of a semiconductor substrate of the present invention, in the method for analyzing metal impurities of any of the first to third semiconductor substrates, the analysis substrate is a silicon substrate. Easy to evaporate and dry the decomposition solution,
It is suitable for analyzing metal impurities by time-of-flight secondary ion mass spectrometry.
【図面の簡単な説明】[Brief description of the drawings]
【図１】 本発明の実施の形態１に係る半導体基板中ま
たは半導体基板表面に含まれる金属不純物の分析方法を
模式的に示す工程図である。FIG. 1 is a process chart schematically showing a method for analyzing metal impurities contained in a semiconductor substrate or on a semiconductor substrate surface according to a first embodiment of the present invention.
１ 分解液、１ａ 内標準物質を添加した分解液、２
内標準物質、３ テフロン容器、４，４ａ マイクロシ
リンジ、５ 半導体基板、６ テフロン皿、７分析用基
板、８ 乾固物、９ 加熱手段、１０ 飛行時間型二次
イオン質量分析装置（ＴＯＦ−ＳＩＭＳ装置）、１１
検量線。1 Decomposition liquid, 1a Decomposition liquid containing internal standard substance, 2
Internal standard material, 3 Teflon container, 4,4a micro syringe, 5 semiconductor substrate, 6 Teflon dish, 7 analysis substrate, 8 dried material, 9 heating means, 10 time-of-flight secondary ion mass spectrometer (TOF-SIMS) Device), 11
Calibration curve.
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.7 識別記号 ＦＩ テーマコート゛(参考） Ｈ０１Ｊ 49/04 Ｇ０１Ｎ 1/28 Ｘ Ｆターム(参考） 2G001 AA05 BA06 CA05 EA04 GA01 GA02 JA12 KA01 LA11 MA05 NA05 NA06 NA10 NA13 NA17 RA02 RA03 RA20 SA12 2G052 AA13 AB27 AC28 AD12 FD09 GA24 4M106 AA01 BA03 BA12 CB01 DH01 DH11 DH55 DH60 5C038 EE02 EE03 EF25 EF26 ──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. 7 Identification symbol FI Theme coat ゛ (Reference) H01J 49/04 G01N 1/28 X F term (Reference) 2G001 AA05 BA06 CA05 EA04 GA01 GA02 JA12 KA01 LA11 MA05 NA05 NA06 NA10 NA13 NA17 RA02 RA03 RA20 SA12 2G052 AA13 AB27 AC28 AD12 FD09 GA24 4M106 AA01 BA03 BA12 CB01 DH01 DH11 DH55 DH60 5C038 EE02 EE03 EF25 EF26
Claims (4)
質として添加した分解液により半導体基板を処理する工
程と、前記半導体基板を処理した分解液を分析用基板上
で乾固する工程と、前記分析用基板上で乾固した成分を
飛行時間型二次イオン質量分析装置により分析する工程
とを備えたことを特徴とする半導体基板の金属不純物の
分析方法。A step of treating the semiconductor substrate with a decomposition solution to which a component not contained in the semiconductor substrate is added as an internal standard; a step of drying the decomposition solution obtained by treating the semiconductor substrate on an analysis substrate; Analyzing a component dried on the substrate for analysis by a time-of-flight secondary ion mass spectrometer.
リウム、ロジウム、ツリウムまたはルテチウムであるこ
とを特徴とする請求項１に記載の半導体基板の金属不純
物の分析方法。2. The method according to claim 1, wherein the internal standard substance added to the decomposition solution is yttrium, rhodium, thulium, or lutetium.
水素、硫酸およびアンモニアの少なくとも１種類の水溶
液からなることを特徴とする請求項１または２に記載の
半導体基板の金属不純物の分析方法。3. The semiconductor substrate according to claim 1, wherein the decomposition solution comprises at least one kind of aqueous solution of hydrofluoric acid, nitric acid, hydrochloric acid, hydrogen peroxide, sulfuric acid and ammonia. Analysis method.
を特徴とする請求項１ないし３のいずれかに記載の半導
体基板の金属不純物の分析方法。4. The method for analyzing metal impurities in a semiconductor substrate according to claim 1, wherein the analysis substrate is a silicon substrate.
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|---|---|---|---|
| JP2000385395A JP2002184828A (en) | 2000-12-19 | 2000-12-19 | Method of analyzing metallic impurities in semiconductor substrate |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000385395A JP2002184828A (en) | 2000-12-19 | 2000-12-19 | Method of analyzing metallic impurities in semiconductor substrate |
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|---|---|
| JP2002184828A true JP2002184828A (en) | 2002-06-28 |
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ID=18852664
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Cited By (6)
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|---|---|---|---|---|
| WO2005052551A1 (en) * | 2003-11-26 | 2005-06-09 | Mitsubishi Denki Kabushiki Kaisha | Method of analyzing trace component |
| JP2005208037A (en) * | 2003-12-22 | 2005-08-04 | Canon Inc | Calibration sample and method for manufacturing the same |
| US7790479B2 (en) * | 2005-03-18 | 2010-09-07 | Alcatel | Method and device for monitoring the contamination of substrate wafers |
| US7811836B2 (en) | 2005-12-28 | 2010-10-12 | Samsung Electronics Co., Ltd. | Methods of manufacturing reference sample substrates for analyzing metal contamination levels |
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2000
- 2000-12-19 JP JP2000385395A patent/JP2002184828A/en active Pending
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2005052551A1 (en) * | 2003-11-26 | 2005-06-09 | Mitsubishi Denki Kabushiki Kaisha | Method of analyzing trace component |
| WO2005052552A1 (en) * | 2003-11-26 | 2005-06-09 | Mitsubishi Denki Kabushiki Kaisha | Method of analyzing minute quantity of content |
| US8796033B2 (en) | 2003-11-26 | 2014-08-05 | Mitsubishi Denki Kabushiki Kaisha | Method of determining minute amounts of additives in polymers |
| JP2005208037A (en) * | 2003-12-22 | 2005-08-04 | Canon Inc | Calibration sample and method for manufacturing the same |
| JP4711326B2 (en) * | 2003-12-22 | 2011-06-29 | キヤノン株式会社 | Preparation method of calibration sample and calibration curve |
| US7790479B2 (en) * | 2005-03-18 | 2010-09-07 | Alcatel | Method and device for monitoring the contamination of substrate wafers |
| US7811836B2 (en) | 2005-12-28 | 2010-10-12 | Samsung Electronics Co., Ltd. | Methods of manufacturing reference sample substrates for analyzing metal contamination levels |
| JP2016095139A (en) * | 2014-11-12 | 2016-05-26 | 株式会社島津製作所 | Manufacture method of specimen plate, specimen plate manufactured thereby, and inclusion substance measurement apparatus using the same |
| CN111189683A (en) * | 2020-01-06 | 2020-05-22 | 中国科学院地质与地球物理研究所 | Preparation method of ion probe liquid sample target |
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