JPH09264801A - Method for measuring stress/strain - Google Patents
Method for measuring stress/strainInfo
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- JPH09264801A JPH09264801A JP7754996A JP7754996A JPH09264801A JP H09264801 A JPH09264801 A JP H09264801A JP 7754996 A JP7754996 A JP 7754996A JP 7754996 A JP7754996 A JP 7754996A JP H09264801 A JPH09264801 A JP H09264801A
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- Prior art keywords
- stress
- strain
- exposed
- distribution
- inside surface
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、半導体基板などの
固体内部の応力・歪み測定方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring stress / strain inside a solid such as a semiconductor substrate.
【０００２】[0002]
【従来の技術】近年、ＤＲＡＭ等の半導体装置（ＬＳ
Ｉ）においては高集積化が進み、素子の微細化が進んで
いる。素子分離やキャパシタなどにおいては、微細化に
伴って、トレンチ構造のものが広く採用されるようにな
った。また、配線においては、内部応力の強い材料が多
く用いられるようになった。2. Description of the Related Art In recent years, semiconductor devices such as DRAMs (LS
In I), high integration is progressing, and device miniaturization is progressing. Along with the miniaturization, a device having a trench structure has been widely adopted for element isolation and capacitors. Further, in wiring, a material having a strong internal stress has come to be often used.
【０００３】このような状況では、ＬＳＩの製造途中
で、基板（ウェハ）中に強大な応力が発生し、結晶欠陥
（転位、積層欠陥など）が生じやすい。この種の結晶欠
陥はＬＳＩの性能を悪化させ、ひどいときには動作不良
を引き起こす。したがって、結晶欠陥の無い（欠陥フリ
ーの）ＬＳＩの製造方法を開発するためには、各製造工
程ごとに、基板に形成された素子構造内部の応力・歪み
を評価することが重要となる。In such a situation, a large stress is generated in the substrate (wafer) during the manufacture of the LSI, and crystal defects (dislocations, stacking faults, etc.) are likely to occur. This type of crystal defect deteriorates the performance of the LSI and, in severe cases, causes malfunction. Therefore, in order to develop a method for manufacturing a crystal defect-free (defect-free) LSI, it is important to evaluate the stress / strain inside the element structure formed on the substrate for each manufacturing process.
【０００４】応力・歪み分布測定方法の１つとして、基
板の上面からレーザ光を入射し、ラマン分光法により応
力・歪みを求め、その分布を求める方法が知られてい
る。しかし、この応力・歪み分布測定方法には以下のよ
うな問題がある。As one of the stress / strain distribution measuring methods, there is known a method in which laser light is incident from the upper surface of a substrate, stress / strain is obtained by Raman spectroscopy, and the distribution thereof is obtained. However, this stress / strain distribution measuring method has the following problems.
【０００５】まず、この応力・歪み分布測定方法は、基
板の表面近傍の応力・歪み分布を求めるのには有効だ
が、レーザ光の波長を変化させない限り、基板の深い部
分の応力・歪み分布を求めるのが困難であるという問題
がある。First, this stress / strain distribution measuring method is effective for obtaining the stress / strain distribution in the vicinity of the surface of the substrate, but unless the wavelength of the laser beam is changed, the stress / strain distribution in the deep portion of the substrate can be obtained. The problem is that it is difficult to find.
【０００６】また、製造工程が進み、基板上に様々な膜
が積層形成さたり、配線が配設されたりすると、レーザ
光が基板まで届かなくなったり、散乱光を検出できなく
なるので、レーザ光の波長を変化させても、基板の応力
・歪み分布を求めるのが困難になるという問題がある。Further, if the manufacturing process progresses and various films are laminated on the substrate or wirings are arranged, the laser light cannot reach the substrate or scattered light cannot be detected. Even if the wavelength is changed, it is difficult to obtain the stress / strain distribution of the substrate.
【０００７】また、ＭＯＳ−ＬＳＩで一般に使用されて
いる（１００）面方位のシリコンウェハを用いた場合、
ウェハ上面から垂直にレーザ光を入射すると、３つある
ラマンモードのうち１つしか分離検出できないため、応
力の成分（３つの垂直成分、３つのせん断成分）を分離
評価できないという問題があった。When a silicon wafer having a (100) plane orientation, which is generally used in MOS-LSI, is used,
When the laser beam is vertically incident from the upper surface of the wafer, only one of the three Raman modes can be separated and detected, so that there is a problem that stress components (three vertical components and three shear components) cannot be separately evaluated.
【０００８】このような問題を解決し、シリコンウェハ
の深さ方向の応力分布を求める方法として、劈開により
シリコンウェハの内面を露出させ、この露出した内面に
レーザ光を垂直に照射して、露出した内面の応力分布を
測定することが提案されいている。この方法によれば、
劈開により（１１０）面が露出するので、２つ以上のラ
マンモードを検出できるようになる。As a method for solving such a problem and obtaining the stress distribution in the depth direction of the silicon wafer, the inner surface of the silicon wafer is exposed by cleavage, and the exposed inner surface is irradiated with laser light vertically to expose it. It has been proposed to measure the stress distribution on the inner surface. According to this method
Since the (110) plane is exposed by the cleavage, two or more Raman modes can be detected.
【０００９】しかしながら、本発明者等の研究によれ
ば、いくつかのケースでは、劈開などにより内面を露出
させると、この露出した内面の応力分布は露出以前のそ
れとは大きく異なるものに変化してしまうことが明らか
になった。However, according to the studies by the present inventors, in some cases, when the inner surface is exposed by cleavage or the like, the stress distribution on the exposed inner surface changes to a significantly different stress distribution from that before the exposure. It became clear that it would end up.
【００１０】[0010]
【発明が解決しようとする課題】上述の如く、従来のラ
マン分光法を用いた応力・歪み分布測定方法は、基板上
に各種膜や配線等が形成されると、基板深さ方向の応力
・歪み分布を求めるのが困難になるという問題があっ
た。さらに、特定の面方位を有するウェハに対しては、
応力成分を分離して求めることが困難であるという問題
があった。As described above, according to the conventional stress / strain distribution measuring method using Raman spectroscopy, when various films and wirings are formed on the substrate, stress in the depth direction of the substrate There is a problem that it is difficult to obtain the strain distribution. Furthermore, for wafers with a specific plane orientation,
There is a problem that it is difficult to obtain the stress component separately.
【００１１】このような問題を解決できる方法として、
劈開などによりウェハの内面を露出させ、この露出した
内面にレーザ光を照射して、露出した内面の応力・歪み
分布を求める方法が提案されていた。As a method for solving such a problem,
A method has been proposed in which the inner surface of the wafer is exposed by cleavage or the like, and the exposed inner surface is irradiated with laser light to obtain the stress / strain distribution of the exposed inner surface.
【００１２】しかし、本発明者等の研究によれば、露出
した内面の応力・歪み分布は、露出以前のそれとは大き
く異なるものに変化し、正確な応力・歪み分布は得られ
ないことが明らかになった。However, according to the research conducted by the present inventors, it is clear that the stress / strain distribution on the exposed inner surface changes to a significantly different distribution from that before the exposure, and an accurate stress / strain distribution cannot be obtained. Became.
【００１３】本発明は、上記事情を考慮してなされたも
ので、その目的とするところは、固体の被測定物の内面
近傍の応力・歪みを正確に求めることができる応力・歪
み測定方法を提供することにある。The present invention has been made in consideration of the above circumstances, and an object thereof is to provide a stress / strain measuring method capable of accurately obtaining stress / strain in the vicinity of the inner surface of a solid object to be measured. To provide.
【００１４】[0014]
［概要］上記目的を達成するために、本発明に係る応力
・歪み測定方法（請求項１）は、固体の被評価物の内面
を露出させる露出工程と、この露出した内面近傍におけ
る応力および歪みの少なくとも一方を測定に基づいて求
める測定工程と、この測定工程の結果に基づいて、前記
内面を露出させる前の前記内面近傍の応力および歪みの
少なくとも一方を求める復元工程とを有することを特徴
とする。[Outline] In order to achieve the above object, a stress / strain measuring method according to the present invention (claim 1) includes an exposing step of exposing an inner surface of a solid object to be evaluated, and stress and strain in the vicinity of the exposed inner surface. Of at least one of the measurement step based on the measurement, based on the result of this measurement step, the inner surface before the exposure of the inner surface near the stress and strain at least one of the restoring step for determining To do.
【００１５】また、本発明に係る他の応力・歪み測定方
法（請求項２）は、上記応力・歪み測定方法（請求項
１）において、前記測定工程が、ラマン分光法を用い
て、前記露出した内面近傍の応力および歪みの少なくと
も一方を求めることを特徴とする。Another stress / strain measuring method according to the present invention (claim 2) is the stress / strain measuring method (claim 1), wherein the measuring step uses Raman spectroscopy. It is characterized in that at least one of stress and strain in the vicinity of the inner surface is obtained.
【００１６】この場合、被測定物として、結晶性半導体
や結晶性金属等の結晶性材料からなるものとなる。ま
た、本発明に係る他の応力・歪み測定方法（請求項３）
は、上記応力・歪み測定方法（請求項１，２）におい
て、前記復元工程は、前記測定工程により求められた応
力および歪みの少なくとも一方に基づいて、弾性解析に
より前記内面を露出させる前の前記内面近傍の応力およ
び歪みの少なくとも一方を求めることを特徴とする。In this case, the object to be measured is made of a crystalline material such as a crystalline semiconductor or a crystalline metal. Further, another stress / strain measuring method according to the present invention (claim 3).
In the stress / strain measuring method (claims 1 and 2), the restoring step is performed before the inner surface is exposed by elastic analysis based on at least one of the stress and the strain obtained in the measuring step. It is characterized in that at least one of stress and strain near the inner surface is obtained.
【００１７】本発明において、内面近傍とは、現在の測
定技術では、露出した表面から１０００ｎｍ程度までの
深さの部分をいう。内面近傍という表現は、測定の際に
必然的に露出した表面からある程度の深さまでの部分を
測定することになるからである。また、上記値は使用す
る測定技術や技術の進歩により変化するものであり、し
たがって、内面近傍の指標となる数値は上記値に限定さ
れるものではない。In the present invention, the vicinity of the inner surface refers to a portion having a depth of about 1000 nm from the exposed surface in the current measuring technique. This is because the expression "in the vicinity of the inner surface" necessarily means measuring a portion from the exposed surface to a certain depth at the time of measurement. Further, the above value changes depending on the measurement technique used and the progress of the technique, and therefore, the numerical values as the index near the inner surface are not limited to the above values.
【００１８】［作用］本発明（請求項１〜請求項３）で
は、露出した内面近傍における応力、歪みの測定結果を
そのまま内面を露出させる前の応力、歪みとするのでは
く、測定工程の結果に基づいて、内面を露出させる前の
内面近傍の応力、歪みを復元するようにしているので、
正確に応力、歪みを求めることができるようになる。[Operation] In the present invention (claims 1 to 3), the measurement result of the stress and strain in the vicinity of the exposed inner surface is not used as the stress and strain before the inner surface is exposed as it is. Based on the results, we try to restore the stress and strain near the inner surface before exposing the inner surface.
It becomes possible to accurately obtain stress and strain.
【００１９】さらに、本発明（請求項２）によれば、ラ
マン分光を用いているので、被測定物の深さ方向につい
て応力をいくつかの応力成分毎に測定することもできる
ようになる。Further, according to the present invention (claim 2), since Raman spectroscopy is used, it becomes possible to measure the stress for each of several stress components in the depth direction of the object to be measured.
【００２０】さらにまた、本発明（請求項３）によれ
ば、弾性解析を用いることにより、応力、歪みの復元を
正確に行なえるようになる。これは本発明者等の研究に
より復元工程において使用する種々のモデルのうち特に
弾性体モデルが有効であることが明らかになったことに
基づく。Furthermore, according to the present invention (claim 3), by using elasticity analysis, the stress and strain can be restored accurately. This is based on the fact that the elastic body model is particularly effective among the various models used in the restoration process by the study of the present inventors.
【００２１】[0021]
【発明の実施の形態】以下、図面を参照しながら本発明
の実施の形態（以下、実施形態という）を説明する。 （第１の実施形態）図１は、本発明による応力分布測定
方法の基本概念を説明するための図である。なお、応力
と歪みとの間には関係があり、応力から歪みを求めるこ
とができ、逆に歪みから応力も求めることができる（特
に弾性体では容易）ので、以下の説明では応力分布測定
方法について説明し、歪み分布測定方法については特に
説明しない。BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention (hereinafter referred to as embodiments) will be described below with reference to the drawings. (First Embodiment) FIG. 1 is a diagram for explaining the basic concept of a stress distribution measuring method according to the present invention. Since there is a relationship between the stress and the strain, and the strain can be obtained from the stress, and conversely, the stress can also be obtained from the strain (especially with an elastic body), the stress distribution measuring method will be described below. Will be described, and the strain distribution measuring method will not be particularly described.
【００２２】まず、図１（ａ）に示すように、被測定物
１の内面２を露出させる。被測定物１は固体であれば良
いが、以下の説明では単結晶のシリコン基板を用いた場
合について説明する。First, as shown in FIG. 1A, the inner surface 2 of the DUT 1 is exposed. The device under test 1 may be a solid, but in the following description, a case of using a single crystal silicon substrate will be described.
【００２３】シリコン基板１の内面を露出させるには、
例えば、シリコン基板１を劈開する（割る）か、または
シリコン基板１をＲＩＥ（Reactive Ion Etching）やＦ
ＩＢ（Focused Ion Beam）などを用いた加工により行な
う。To expose the inner surface of the silicon substrate 1,
For example, the silicon substrate 1 is cleaved (divided), or the silicon substrate 1 is subjected to RIE (Reactive Ion Etching) or F.
This is performed by processing using IB (Focused Ion Beam) or the like.
【００２４】次に図１（ｂ）に示すように、レーザラマ
ン分光法を用いて、露出した内面近傍におけるラマンシ
フト量またはラマン散乱強度、もしくはこれら両方を測
定し、得られたラマンシフト量またはラマン散乱強度、
もしくはこれら両方から露出した内面近傍における応力
分布３を求める。Next, as shown in FIG. 1B, the Raman shift amount and / or the Raman scattering intensity in the vicinity of the exposed inner surface are measured by laser Raman spectroscopy, and the obtained Raman shift amount or Raman is obtained. Scattering intensity,
Alternatively, the stress distribution 3 near the inner surface exposed from both of them is obtained.
【００２５】ここで、露出した内面の多数の箇所にレー
ザ光を照射し、各箇所におけるラマンシフト量等を測定
して応力分布を求めても良いが、露出した内面の数箇所
だけにレーザ光を照射し、数箇所だけのラマンシフト量
等を測定するだけも良い。この場合、数点の応力しか分
からないので、いわゆる分布は求められない。Here, the stress distribution may be obtained by irradiating a large number of locations on the exposed inner surface with laser light and measuring the amount of Raman shift or the like at each location, but the laser light may be applied only to a few locations on the exposed inner surface. It is also possible to irradiate the laser beam and measure the Raman shift amount at only a few places. In this case, a so-called distribution cannot be obtained because only a few stress points are known.
【００２６】次に図１（ｃ）に示すように、上記測定の
結果に基づいて、３次元応力シミュレーションによる弾
性解析を行なって、内面２を露出する前（破壊前）の内
面の応力分布３ａを計算により求める。このようにして
被測定物１の深さ方向の応力分布を正確に求めることが
できるようになる。Next, as shown in FIG. 1 (c), elasticity analysis by three-dimensional stress simulation is performed on the basis of the result of the above measurement, and the stress distribution 3a of the inner surface 2 before the inner surface 2 is exposed (before fracture). Is calculated. In this way, the stress distribution in the depth direction of the DUT 1 can be accurately obtained.
【００２７】このような応力分布測定方法を用いれば、
各製造工程における基板に形成された素子構造内部の深
さ方向の応力分布を正確に測定することができ、各製造
工程における基板に形成された素子構造内部の応力・歪
みを評価できるようになる。If such a stress distribution measuring method is used,
It is possible to accurately measure the stress distribution in the depth direction inside the element structure formed on the substrate in each manufacturing process, and to evaluate the stress and strain inside the element structure formed on the substrate in each manufacturing process. .
【００２８】図２、図３は、本発明を表面にトレンチが
形成されたシリコン基板に適用した例を説明するための
図である。図２は被測定物の内面を露出させる前の状態
を示し、図３は露出させた後の状態を示している。これ
ら図では被測定物をメッシュ図により示している。2 and 3 are views for explaining an example in which the present invention is applied to a silicon substrate having a trench formed on the surface. 2 shows a state before the inner surface of the object to be measured is exposed, and FIG. 3 shows a state after the inner surface is exposed. In these figures, the object to be measured is shown by a mesh diagram.
【００２９】まず、図３に示すような被測定物を用意す
る。図中、１は単結晶のシリコン基板を示しており、こ
のシリコン基板１の表面には、幅１μｍ、深さ４μｍの
ストライプ状のトレンチ５が形成されている。このトレ
ンチ５は、図中、奥行き方向に伸びている。First, an object to be measured as shown in FIG. 3 is prepared. In the figure, 1 indicates a single crystal silicon substrate, and a stripe-shaped trench 5 having a width of 1 μm and a depth of 4 μm is formed on the surface of the silicon substrate 1. The trench 5 extends in the depth direction in the figure.
【００３０】このトレンチ５内には、ＳｉＯ2 膜４が埋
め込み形成されている。このＳｉＯ2 膜４の成膜材料に
はＴＥＯＳ系の材料が用いられている。このＳｉＯ2 膜
４は成膜後にＮ2 雰囲気中での１０００℃、１時間の熱
処理が施されている。A SiO 2 film 4 is buried in the trench 5. A TEOS-based material is used as a material for forming the SiO 2 film 4. The SiO 2 film 4 is heat-treated at 1000 ° C. for 1 hour in an N 2 atmosphere after the film formation.
【００３１】次に図３に示すように、上記被測定物をｙ
−ｚ平面に平行な面で劈開し、露出した内面である自由
変位可能な面６に垂直にレーザ光を入射し、偏光ラマン
測定により、露出した面内近傍の応力分布を求める。Next, as shown in FIG.
-Cleavage is performed on a plane parallel to the z-plane, laser light is vertically incident on the freely displaceable surface 6 which is an exposed inner surface, and the stress distribution near the exposed in-plane is obtained by polarization Raman measurement.
【００３２】一方、露出した内面近傍の応力分布を計算
により求める。まず、図２と同一構造の被測定物につい
て、１０００℃から室温まで温度を下げるときに発生す
る応力を３次元シミュレーションによる弾性解析により
求める。すなわち、劈開前の内面の応力分布を計算によ
り求める。On the other hand, the stress distribution near the exposed inner surface is calculated. First, for an object to be measured having the same structure as in FIG. 2, the stress generated when the temperature is lowered from 1000 ° C. to room temperature is obtained by elastic analysis by three-dimensional simulation. That is, the stress distribution on the inner surface before cleavage is calculated.
【００３３】ここでは、１０００℃から室温まで温度を
下げるときに、シリコン基板１とＳｉＯ2 膜４との間で
熱膨脹係数の違いにより応力が発生するというモデルで
計算を行なう。Here, calculation is performed by a model in which stress is generated between the silicon substrate 1 and the SiO 2 film 4 due to the difference in thermal expansion coefficient when the temperature is lowered from 1000 ° C. to room temperature.
【００３４】次に劈開を考慮するため、つまり、露出し
た内面近傍の応力分布を求めるために、一つの端面（図
では手前ｙ−ｚ面）の境界条件を変えて計算を行なう。
すなわち、劈開前は図２に示すように、ｘ軸方向に連続
面（対称面）として扱っていた手前のｙ−ｚ面を、図３
に示すように、自由変位可能な面６に変更する計算を、
温度一定の条件で弾性解析で行なう。Next, in order to consider the cleavage, that is, in order to obtain the stress distribution in the vicinity of the exposed inner surface, the calculation is performed by changing the boundary condition of one end surface (the front yz surface in the figure).
That is, as shown in FIG. 2 before cleavage, the yz plane in front, which was treated as a continuous surface (symmetrical surface) in the x-axis direction,
As shown in, the calculation for changing to the freely displaceable surface 6,
Elasticity analysis is performed under constant temperature conditions.
【００３５】そして、上記ラマン測定の結果と、上記シ
ミュレーションの結果が劈開面内全体でよく一致するよ
うに、シミュレーションで用いる物性パラメータを最適
化する。結果の比較は、応力ではなく、ラマンシフトを
比較するようにした。Then, the physical property parameters used in the simulation are optimized so that the result of the Raman measurement and the result of the simulation are well matched in the entire cleavage plane. The comparison of results was made to compare Raman shifts, not stress.
【００３６】この最適化の過程で、物性パラメータとし
て、弾性定数（弾性マトリクス、ヤング率）、線膨脹係
数、ポアソン比を最適化すれば良いことが分かった。こ
のとき、シリコンの応力には異方性があると仮定し、Ｓ
ｉＯ2 の応力には異方性がなく等方性と仮定した。表１
に、最適化された物性パラメータの数値を示す。In the process of this optimization, it has been found that the elastic constants (elastic matrix, Young's modulus), linear expansion coefficient, and Poisson's ratio may be optimized as physical property parameters. At this time, assuming that the stress of silicon has anisotropy, S
The stress of iO 2 was assumed to be isotropic without any anisotropy. Table 1
Shows the numerical values of the optimized physical property parameters.
【００３７】[0037]
【表１】 [Table 1]
【００３８】上記最適化の作業は、コンピュータを用い
て容易に行なうことができる。すなわち、露出した内面
（劈開面）およびその近傍における応力、歪み、ラマン
シフトなどの物理量の実験値とシミュレーションによる
計算値との差が、ある値以下になるまで、上記パラメー
タ（ポアソン比、ヤング率、線熱膨脹係数など）を変化
させる。The above optimization work can be easily performed using a computer. That is, the above parameters (Poisson's ratio, Young's modulus) are kept until the difference between the experimental value of the physical quantity such as stress, strain, Raman shift, etc. and the calculated value on the exposed inner surface (cleavage surface) and its vicinity becomes less than a certain value , Linear thermal expansion coefficient, etc.).
【００３９】次に得られた最適化された物性パラメータ
およびラマン測定の結果（応力分布）を用いて、境界条
件を「断面自由変位」から「連続面（対称面）」に変更
し、３次元弾性解析を行なうことにより、内面を露出す
る前の応力分布を求める。Next, using the obtained optimized physical property parameters and the result of Raman measurement (stress distribution), the boundary condition is changed from "section free displacement" to "continuous surface (symmetric surface)" and three-dimensional. By performing elastic analysis, the stress distribution before exposing the inner surface is obtained.
【００４０】図４〜図９に、上記方法に従って、露出し
た（劈開状態）の内面近傍の応力分布から、内面を露出
させる前（バルク状態）の該内面近傍の応力分布を復元
した様子を示す。FIGS. 4 to 9 show how the stress distribution near the inner surface before the inner surface is exposed (in the bulk state) is restored from the stress distribution near the inner surface when the inner surface is exposed (cleavage state) according to the above method. .
【００４１】図４、図５はそれぞれバルク状態、劈開状
態の場合のｙ方向（水平方向）応力成分（Ｓｙｙ）の分
布を示し、図６、図７はそれぞれバルク状態、劈開状態
の場合のｚ方向（垂直方向）応力成分（Ｓｚｚ）の分布
を示し、そして、図８、図９はそれぞれバルク状態、劈
開状態の場合のｘ方向（奥行き方向）応力成分（Ｓｘ
ｘ）の分布を示している（ＳｉＯ2 は省略）。また、マ
イナスの応力値は圧縮を表し、プラスの応力値は引っ張
りを表わす。4 and 5 show the distribution of the y-direction (horizontal direction) stress component (Syy) in the bulk state and the cleaved state, and FIGS. 6 and 7 show z in the bulk state and the cleaved state, respectively. The distribution of the directional (vertical) stress component (Szz) is shown, and FIGS. 8 and 9 show the x-direction (depth direction) stress component (Sx) in the bulk state and the cleaved state, respectively.
The distribution of x) is shown (SiO 2 is omitted). Also, a negative stress value represents compression and a positive stress value represents tension.
【００４２】これら図から、劈開の前後で、応力の奥行
き成分と垂直成分は大きく変化し、水平成分はあまり変
化しないことがことが分かる。すなわち、劈開の影響を
考慮しないと劈開以前の正確な応力分布を求められない
ことが分かる。From these figures, it is understood that the depth component and the vertical component of the stress largely change before and after the cleavage, but the horizontal component does not change so much. That is, it can be seen that an accurate stress distribution before cleavage cannot be obtained unless the influence of cleavage is taken into consideration.
【００４３】劈開面から離れた場所で被測定物を上面か
らレーザラマン分光により測定した結果、上記のように
劈開面で物性パラメータを最適化した計算結果の方が良
く合うことが分かった。As a result of measuring the object to be measured from the top surface by laser Raman spectroscopy at a location apart from the cleavage plane, it was found that the calculation results obtained by optimizing the physical property parameters on the cleavage plane as described above fit better.
【００４４】ここでは、ラマン測定の結果と、シミュレ
ーションの結果が露出面（劈開面）内の大部分（２／３
以上のメッシュ）で良く一致するように、シミュレーシ
ョンで用いる物性パラメータを最適化したが、物性パラ
メータのフィッティングを劈開面内全体で正確に行なう
のが煩雑で煩わしい場合は、劈開面上数カ所で実験とシ
ミュレーションを合わせ込むだけでも良い。本発明者等
はこの場合でも従来に比べて十分に正確な応力分布を求
められることを確認した。Here, the results of the Raman measurement and the results of the simulation show that most of the results (2/3) in the exposed surface (cleavage surface).
The physical property parameters used in the simulation were optimized so that they would match well with the above mesh), but if accurate fitting of the physical property parameters in the entire cleavage plane is cumbersome and cumbersome, experiments should be performed at several locations on the cleavage plane. You only need to match the simulation. The present inventors have confirmed that even in this case, a sufficiently accurate stress distribution can be obtained as compared with the conventional case.
【００４５】なお、本発明は上述した実施例に限定され
るものではない。例えば、あらかじめ最適化された物性
パラメータが分かっている場合には、ラマン測定の結果
と、シミュレーションの結果を一致させる工程は省くこ
とができ、ラマン測定の結果（応力分布）と最適化され
た物性パラメータを用いて、境界条件を「断面自由変
位」から「連続面（対称面）」に変更し、３次元弾性解
析を行なうことにより、内面を露出する前の応力分布を
求めることが可能となる。その他、本発明の要旨を逸脱
しない範囲で、種々変形して実施できる。The present invention is not limited to the above embodiment. For example, if the optimized physical property parameters are known in advance, the step of matching the Raman measurement result with the simulation result can be omitted, and the Raman measurement result (stress distribution) and the optimized physical property can be omitted. It is possible to determine the stress distribution before the inner surface is exposed by changing the boundary condition from "section free displacement" to "continuous surface (symmetrical surface)" using parameters and performing three-dimensional elastic analysis. . In addition, various modifications can be made without departing from the scope of the present invention.
【００４６】[0046]
【発明の効果】以上詳述したように本発明によれば、露
出した内面近傍における応力、歪みの測定結果をそのま
ま内面を露出させる前の応力、歪みとするのではく、測
定工程の結果に基づいて、内面を露出させる前の内面近
傍の応力、歪みを復元するようにしているので、正確な
応力、歪みを求めることができるようになる。As described above in detail, according to the present invention, the measurement result of the stress and strain in the vicinity of the exposed inner surface is not the stress and strain before the inner surface is exposed as it is, Since the stress and strain in the vicinity of the inner surface before the inner surface is exposed are restored based on this, accurate stress and strain can be obtained.
【図１】本発明による応力分布測定方法の基本概念を説
明するための図FIG. 1 is a diagram for explaining the basic concept of a stress distribution measuring method according to the present invention.
【図２】被測定物の内面を露出させる前の状態を示す図FIG. 2 is a diagram showing a state before the inner surface of the measured object is exposed.
【図３】被測定物の内面を露出させた後の状態を示す図FIG. 3 is a diagram showing a state after the inner surface of the measured object is exposed.
【図４】バルク状態の場合の水平応力成分の分布を示す
図FIG. 4 is a diagram showing distribution of horizontal stress components in a bulk state.
【図５】劈開状態の場合の水平応力成分の分布を示す図FIG. 5 is a diagram showing a distribution of horizontal stress components in a cleaved state.
【図６】バルク状態の場合の垂直応力成分の分布を示す
図FIG. 6 is a diagram showing distribution of vertical stress components in a bulk state.
【図７】劈開状態の場合の垂直応力成分の分布を示す図FIG. 7 is a diagram showing the distribution of vertical stress components in the cleaved state.
【図８】バルク状態の場合の奥行き応力成分の分布を示
す図FIG. 8 is a diagram showing the distribution of depth stress components in the bulk state.
【図９】劈開状態の場合の奥行き応力成分の分布を示す
図FIG. 9 is a diagram showing a distribution of depth stress components in a cleaved state.
１…シリコン基板（被測定物） ２…露出した内面 ３…露出した内面近傍の応力分布 ４…ＳｉＯ2 膜 ５…トレンチ ６…露出した内面（自由変位可能な面）1 ... Silicon substrate (measurement object) 2 ... Exposed inner surface 3 ... Stress distribution in the vicinity of the exposed inner surface 4 ... SiO 2 film 5 ... Trench 6 ... Exposed inner surface (freely displaceable surface)
Claims (3)
程と、 この露出した内面近傍における応力および歪みの少なく
とも一方を測定に基づいて求める測定工程と、 この測定工程の結果に基づいて、前記内面を露出させる
前の前記内面近傍の応力および歪みの少なくとも一方を
求める復元工程とを有することを特徴とする応力・歪み
測定方法。1. An exposing step for exposing an inner surface of a solid object to be evaluated, a measuring step for obtaining at least one of stress and strain in the vicinity of the exposed inner surface on the basis of measurement, and based on a result of the measuring step, A stress / strain measuring method, comprising a restoring step of obtaining at least one of stress and strain in the vicinity of the inner surface before exposing the inner surface.
前記露出した内面近傍の応力および歪みの少なくとも一
方を求めることを特徴とする請求項１に記載の応力・歪
み測定方法。2. The measuring step uses Raman spectroscopy,
The stress / strain measuring method according to claim 1, wherein at least one of stress and strain near the exposed inner surface is obtained.
られた応力および歪みの少なくとも一方に基づいて、弾
性解析により前記内面を露出させる前の前記内面近傍の
応力および歪みの少なくとも一方を求めることを特徴と
する請求項１または請求項２に記載の応力・歪み測定方
法。3. The restoring step determines at least one of stress and strain in the vicinity of the inner surface before the inner surface is exposed by elasticity analysis based on at least one of stress and strain obtained in the measuring step. The stress / strain measuring method according to claim 1 or 2.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7754996A JPH09264801A (en) | 1996-03-29 | 1996-03-29 | Method for measuring stress/strain |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7754996A JPH09264801A (en) | 1996-03-29 | 1996-03-29 | Method for measuring stress/strain |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH09264801A true JPH09264801A (en) | 1997-10-07 |
Family
ID=13637105
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7754996A Pending JPH09264801A (en) | 1996-03-29 | 1996-03-29 | Method for measuring stress/strain |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH09264801A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007200026A (en) * | 2006-01-26 | 2007-08-09 | Daihatsu Motor Co Ltd | Surface distortion evaluation device and method |
| JP2009168562A (en) * | 2008-01-15 | 2009-07-30 | Fujitsu Ltd | Stress evaluating method using raman spectroscopy, and method of manufacturing semiconductor device |
-
1996
- 1996-03-29 JP JP7754996A patent/JPH09264801A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007200026A (en) * | 2006-01-26 | 2007-08-09 | Daihatsu Motor Co Ltd | Surface distortion evaluation device and method |
| JP2009168562A (en) * | 2008-01-15 | 2009-07-30 | Fujitsu Ltd | Stress evaluating method using raman spectroscopy, and method of manufacturing semiconductor device |
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