JPH0443661A - Evaluation method of constituent material for semiconductor element - Google Patents
Evaluation method of constituent material for semiconductor elementInfo
- Publication number
- JPH0443661A JPH0443661A JP15220190A JP15220190A JPH0443661A JP H0443661 A JPH0443661 A JP H0443661A JP 15220190 A JP15220190 A JP 15220190A JP 15220190 A JP15220190 A JP 15220190A JP H0443661 A JPH0443661 A JP H0443661A
- Authority
- JP
- Japan
- Prior art keywords
- raman
- intensity
- crystal grain
- beam diameter
- orientation
- 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
- 239000000463 material Substances 0.000 title claims abstract description 33
- 239000004065 semiconductor Substances 0.000 title claims abstract description 30
- 239000000470 constituent Substances 0.000 title claims abstract description 8
- 238000011156 evaluation Methods 0.000 title abstract description 6
- 239000013078 crystal Substances 0.000 claims abstract description 92
- 238000001069 Raman spectroscopy Methods 0.000 claims abstract description 55
- 238000000034 method Methods 0.000 claims abstract description 32
- 238000005259 measurement Methods 0.000 claims description 15
- 230000010287 polarization Effects 0.000 claims description 10
- 238000004519 manufacturing process Methods 0.000 claims description 6
- 238000012805 post-processing Methods 0.000 claims description 2
- 229910021420 polycrystalline silicon Inorganic materials 0.000 abstract description 7
- 229920005591 polysilicon Polymers 0.000 abstract description 6
- 239000000758 substrate Substances 0.000 abstract description 6
- 239000002245 particle Substances 0.000 abstract description 5
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 abstract description 4
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 abstract description 3
- 229910052710 silicon Inorganic materials 0.000 abstract description 3
- 239000010703 silicon Substances 0.000 abstract description 3
- 229910052786 argon Inorganic materials 0.000 abstract description 2
- 230000003595 spectral effect Effects 0.000 abstract 1
- 210000003323 beak Anatomy 0.000 description 12
- 239000010408 film Substances 0.000 description 9
- 238000005530 etching Methods 0.000 description 8
- 238000010586 diagram Methods 0.000 description 7
- 238000009826 distribution Methods 0.000 description 5
- 238000002441 X-ray diffraction Methods 0.000 description 4
- 235000012431 wafers Nutrition 0.000 description 4
- 230000007547 defect Effects 0.000 description 3
- 230000001066 destructive effect Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000005281 excited state Effects 0.000 description 2
- 238000007689 inspection Methods 0.000 description 2
- 230000001678 irradiating effect Effects 0.000 description 2
- 238000005224 laser annealing Methods 0.000 description 2
- 238000000691 measurement method Methods 0.000 description 2
- 230000003287 optical effect Effects 0.000 description 2
- CVOFKRWYWCSDMA-UHFFFAOYSA-N 2-chloro-n-(2,6-diethylphenyl)-n-(methoxymethyl)acetamide;2,6-dinitro-n,n-dipropyl-4-(trifluoromethyl)aniline Chemical compound CCC1=CC=CC(CC)=C1N(COC)C(=O)CCl.CCCN(CCC)C1=C([N+]([O-])=O)C=C(C(F)(F)F)C=C1[N+]([O-])=O CVOFKRWYWCSDMA-UHFFFAOYSA-N 0.000 description 1
- 244000223014 Syzygium aromaticum Species 0.000 description 1
- 235000016639 Syzygium aromaticum Nutrition 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 238000005324 grain boundary diffusion Methods 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 238000013508 migration Methods 0.000 description 1
- 230000005012 migration Effects 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000000790 scattering method Methods 0.000 description 1
- 229910021332 silicide Inorganic materials 0.000 description 1
- FVBUAEGBCNSCDD-UHFFFAOYSA-N silicide(4-) Chemical compound [Si-4] FVBUAEGBCNSCDD-UHFFFAOYSA-N 0.000 description 1
- 235000014347 soups Nutrition 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
Landscapes
- Testing Or Measuring Of Semiconductors Or The Like (AREA)
Abstract
Description
【発明の詳細な説明】
［慨要］
半導体素子構成材料を非破壊で評価する半導体の評価方
法に関し、
ラマン散乱法を用いて半導体素子を構成する多結晶材料
の結晶粒径を非破壊で測定でき、さらに必要によりその
方位を測定できる方法を提供することを目的とし、
半導体素子を構成する多結晶材料の表面を第１のビーム
径を有するレーザービームで走査し、ラマン散乱ピーク
の強度が前記走査の方向で変化する第１の強度変化を求
め、第１のビーム径より小さい第２のビーム径を有する
レーザービームによる走査を行ってラマン散乱ピークの
強度が前記走査方向で変化する第２の強度変化を求め、
第１の強度変化と第２の強度変化を比較し、ラマン分光
法による測定精度以上の強度変化があった時に、結晶粒
径が第１のビーム径より小でかつ第２のビーム径より大
であると確定するように構成する。[Detailed Description of the Invention] [Summary] Regarding a semiconductor evaluation method for non-destructively evaluating semiconductor element constituent materials, the crystal grain size of a polycrystalline material constituting a semiconductor element is measured non-destructively using a Raman scattering method. The purpose of the present invention is to provide a method in which the surface of a polycrystalline material constituting a semiconductor element is scanned with a laser beam having a first beam diameter, and the intensity of the Raman scattering peak is determined as described above. A first intensity change that changes in the scanning direction is obtained, and scanning is performed with a laser beam having a second beam diameter smaller than the first beam diameter to obtain a second intensity change in which the intensity of the Raman scattering peak changes in the scanning direction. Find the strength change,
Compare the first intensity change and the second intensity change, and if there is an intensity change that exceeds the measurement accuracy by Raman spectroscopy, it is determined that the crystal grain size is smaller than the first beam diameter and larger than the second beam diameter. The configuration is configured so that it is determined that
［産業上の利用分野］
本発明は、半導体素子構成材料を非破壊で評価する半導
体の評価方法に関する。[Industrial Application Field] The present invention relates to a semiconductor evaluation method for non-destructively evaluating semiconductor element constituent materials.
近年の半導体の高集積化に伴い、信頬性の高い半導体材
料が求められている。例えば、基板上に堆積したポリシ
リコン、アルミニウム、シリサイドなどの材料からなる
膜の結晶性は、半導体素子の移動度などの電気的特性に
大きく影響を及ぼすため、基板上で膜は同一の面方位で
ありかつ均一な結晶粒径であることが要求されている。With the recent trend toward higher integration of semiconductors, there is a need for semiconductor materials with high reliability. For example, the crystallinity of films made of materials such as polysilicon, aluminum, and silicide deposited on a substrate greatly affects the electrical properties such as the mobility of semiconductor devices, so the crystallinity of films deposited on a substrate has the same plane orientation. and uniform crystal grain size.
理想的には、絶縁基板上の膜が単結晶であるのがよいが
、実際の膜は基板上で多結晶であるため各結晶粒の方位
のずれや粒径の差が生じている。このため、その結晶性
を評価する必要がある。Ideally, the film on the insulating substrate should be single crystal, but in reality, the film is polycrystalline on the substrate, so that the orientation of each crystal grain is misaligned and the grain size differs. Therefore, it is necessary to evaluate its crystallinity.
従来の結晶性評価方法としては、エツチング法やＸ線回
折法がある。前者はエツチング液に浸漬することで、エ
ツチング速度の結晶面依存性を利用し、表面凹凸を形成
していた。エツチング液によって、欠陥の種類や面方位
が異なるので、適切なエツチング液を選択することで結
晶粒径や欠陥密度の情報を得ていた。又、Ｘ線回折法は
、結晶性を評価する方法としては古くから用いられてい
るもので、試料からのＸ線の回折角度によって、置方イ
☆を知ることができる。Conventional crystallinity evaluation methods include etching method and X-ray diffraction method. The former uses the dependence of etching rate on crystal planes to form surface irregularities by immersing it in an etching solution. Since the type and plane orientation of defects vary depending on the etching solution, information on crystal grain size and defect density can be obtained by selecting an appropriate etching solution. Furthermore, the X-ray diffraction method has been used for a long time as a method for evaluating crystallinity, and it is possible to determine the placement A☆ from the diffraction angle of X-rays from the sample.
近年ラマン散乱による半導体材料の評価が行われるよう
になった（Ｓｅｍｉｃｏｎｄｕｃｔｏｒ Ｗｏｒｌｄ、
１９８９゜８、 ｐ８９〜９６参照）。光と物質の相
互作用によって物質の励起状態が作りだされ、この励起
エネルギに相当する分だけ光のエネルギが変化し、入射
光と散乱光の波長の差が数ｃｍ−’以上の場合をラマン
散乱ど０平ぶ。In recent years, semiconductor materials have been evaluated using Raman scattering (Semiconductor World,
1989°8, p.89-96). The interaction between light and matter creates an excited state in the matter, the energy of the light changes by an amount corresponding to this excitation energy, and the case where the difference in wavelength between the incident light and the scattered light is several cm-' or more is called Raman. Scattered 0 flat.
物質の励起状態として結晶格子の振動（フォノン）を考
えると、その振動数は原子間の結合力の平方根に比例し
、結合力は原子間結合距離に比例する。この性質を利用
して結晶欠陥による結晶の周期性の乱れなどが評価され
ることが提案されている。また、フォノンは結晶中を伝
搬する波であるので、結晶の周期や対称性を反映する性
質を利用して人工超格子の周期や積層構造の評価が行わ
れている。Considering the vibrations (phonons) of a crystal lattice as the excited state of a substance, its frequency is proportional to the square root of the bonding force between atoms, and the bonding force is proportional to the bonding distance between atoms. It has been proposed that this property can be used to evaluate disturbances in crystal periodicity due to crystal defects. Furthermore, since phonons are waves that propagate in crystals, the periodicity and stacked structure of artificial superlattices are evaluated using properties that reflect the periodicity and symmetry of crystals.
さらに走査型偏光ラマン顕微装置を用い、ラマン敗乱強
度が入射、散乱光の偏光ベクトルの向きに依存して結晶
の方位を決定する性質を利用して、レーザーアニールさ
れたシリコン薄膜の結晶方位の測定が行われている（前
掲Ｓｅｍ１ｃｏｎｄｕｃｔｏｒＷｏｒｌｄ ）。この場
合の方位測定はラマン敢乱強度は入りｊ光、散乱光の偏
光方向と結晶軸との相対関係によって著しく変化するこ
とを利用している。Furthermore, using a scanning polarization Raman microscope, the crystal orientation of the laser-annealed silicon thin film was determined by utilizing the property that the Raman failure intensity determines the crystal orientation depending on the direction of the polarization vector of the incident and scattered light. Measurements are being carried out (Sem1conductorWorld, supra). The orientation measurement in this case utilizes the fact that the Raman scattering intensity changes significantly depending on the relative relationship between the polarization direction of the incident light and scattered light and the crystal axis.
第４図（Ａ）、（Ｂ）、（ｃ）に示すダイアモンド型単
結晶に対する後方散乱配置でのラマン敗乱強度に例をと
って方位測定法の原理を説明する。The principle of the orientation measurement method will be explained by taking as an example the Raman failure intensity in the backscattering arrangement for a diamond-type single crystal shown in FIGS. 4(A), (B), and (c).
なお、後方散乱配貢とは大１１１光の入ｑ＝を側と散乱
光の出射光側を試料に対して同じ側にする配百方法であ
る。図中横軸は試！４の回転角度を示し、縦軸はラマン
敗乱強度（任意単位）を示す。また実線と点線は大ｑ寸
光又は出射光の偏光方向の角度を９０°ずらしているこ
とを意味している。Note that backscattering distribution is a distribution method in which the input side of the large 111 light and the output side of the scattered light are on the same side with respect to the sample. The horizontal axis in the figure is the trial! The rotation angle of 4 is shown, and the vertical axis shows the Raman failure intensity (arbitrary unit). Further, the solid line and the dotted line mean that the angle of the polarization direction of the large q-dimensional light or the emitted light is shifted by 90°.
（１１１）面は回転角度に関係なくラマンビーク強度が
一定しているので、このような強度分布が得られた時は
被測定材料の方位は（１１１）面方位であると定められ
る（第４図（Ｃ）？照）。Since the Raman beak intensity of the (111) plane is constant regardless of the rotation angle, when such an intensity distribution is obtained, the orientation of the material to be measured is determined to be the (111) plane orientation (Figure 4). (C)?Sho).
（１００）面は実線又は点線の１回の測定では（１１０
）面の点線と区別が付かないので、出射された光の偏光
方向を９０°角度をずらして測定を行い、第４図（Ａ）
の二つの曲線が得られると、（１００）面方位を定める
ことができる。同様に（１１０）面は１回の測定で実線
が得られると、（１１０）面であると定められるが、点
線が得られた場合は更に測定を行い実線と点線の両方か
ら（１１０）面であると定めることができる（第４図（
Ｂ）参照）。(100) plane is (110) in one measurement of solid line or dotted line.
), so the polarization direction of the emitted light was shifted by 90 degrees and the measurement was performed, as shown in Figure 4 (A).
Once the two curves are obtained, the (100) plane orientation can be determined. Similarly, if a solid line is obtained in one measurement, the (110) plane is determined to be a (110) plane, but if a dotted line is obtained, additional measurements are performed and both the solid line and the dotted line are determined to be the (110) plane. It can be determined that (Figure 4 (
See B).
以上のような原理を応用してレーザーアニールをしたポ
リシリコンの方位を測定し、また金属顕微鏡で測定した
グレインバウンダリ検出とを合わせてレーザーアニール
の効果が評価されている。The effects of laser annealing are being evaluated by applying the principles described above to measure the orientation of laser-annealed polysilicon, and also by detecting grain boundaries measured using a metallurgical microscope.
［発明が解決しようとする課題］
従来の結晶粒径測定法のエツチング法は破壊検査法であ
り、エツチング液に浸漬した試料は結晶粒界が優先的に
侵されるので、その上に半導体素子構成材料を堆積する
ことはできない。[Problems to be Solved by the Invention] The etching method used in the conventional crystal grain size measurement method is a destructive inspection method, and since the crystal grain boundaries of a sample immersed in an etching solution are preferentially attacked, it is difficult to measure the semiconductor element structure on top of the grain boundaries. Material cannot be deposited.
又、Ｘ線回折法は用いるビーム径が太きく（〉数１００
μｍ）、結晶面方位に関する平均的情報しか得られない
。In addition, the beam diameter used in the X-ray diffraction method is large (> several hundred
μm), only average information regarding crystal plane orientation can be obtained.
従って、結晶性を評価するため、結晶粒の半導体素子の
大きさに対応する小面積の膜中の結晶粒の大きさやその
成長方向を、非破壊で評価することができなかった。Therefore, in order to evaluate crystallinity, it has not been possible to non-destructively evaluate the size of crystal grains in a film with a small area corresponding to the size of the crystal grains of a semiconductor element and the direction of their growth.
本発明は、ラマン散乱法を用いて半導体素子を構成する
多結晶材料の結晶粒径を非破壊で測定でき、さらに必要
によりその方位も測定できる方法を提供することを目的
とする。An object of the present invention is to provide a method that can non-destructively measure the crystal grain size of a polycrystalline material constituting a semiconductor element using Raman scattering, and also measure the orientation if necessary.
本発明は半導体素子を構成する多結晶材料の表面を第１
のビーム径を有するレーザービームで走査し、ラマン散
乱ピークの強度が前記走査の方向で変化する第１の強度
変化を求め、第１のビーム径より小さい第２のビーム径
を有するレーザービームによる走査を行ってラマン散乱
ピークの強度が前記走査方向で変化する第２の強度変化
を求め、第１の強度変化と第２の強度変化を比較し、ラ
マン分光法による測定精度以上の強度変化があった時に
、結晶粒径が第１のビーム径より小でかつ第２のビーム
径より大であると確定することを特徴とする半導体素子
構成材料の評価方法である。以下、本発明の詳細な説明
する。In the present invention, the surface of a polycrystalline material constituting a semiconductor element is
scanning with a laser beam having a beam diameter of , obtaining a first intensity change in which the intensity of the Raman scattering peak changes in the scanning direction, scanning with a laser beam having a second beam diameter smaller than the first beam diameter; The second intensity change in which the intensity of the Raman scattering peak changes in the scanning direction is determined by comparing the first intensity change and the second intensity change, and it is determined whether the intensity change exceeds the measurement accuracy by Raman spectroscopy. This is a method for evaluating a semiconductor element constituent material, characterized in that the crystal grain size is determined to be smaller than a first beam diameter and larger than a second beam diameter when The present invention will be explained in detail below.
第１．２図は、本発明の原理図である。第１図（Ａ）、
（Ｂ）は、顕微鏡の対物レンズ倍率を変えたときの試料
上に集光されたレーザ光１の径を表している。例えば、
第１図（Ａ）は対物レンズ２の倍率が２０倍の場合試料
３上のビームスポット４５ｕｍ、第１図（Ｂ）は対物レ
ンズ２の倍率を１００倍にすると試料３上のビーム径が
１μｍ程度になる。FIG. 1.2 is a diagram of the principle of the present invention. Figure 1 (A),
(B) represents the diameter of the laser beam 1 focused on the sample when the magnification of the objective lens of the microscope is changed. for example,
Figure 1 (A) shows a beam spot on the sample 3 of 45 um when the magnification of the objective lens 2 is 20x, and Figure 1 (B) shows a beam spot of 1 μm on the sample 3 when the magnification of the objective lens 2 is 100x. It will be about.
第２因は、結晶粒の大きさが異なる試料を回転させて照
射した場合に得られるラマン散乱のビーク強度を縦軸に
、走査距離または回転角度を横軸にとり表したものであ
り、同図（Ａ）、（Ｂ）はそれぞれスポットビーム径が
大きい場合と小さい場合を示す。結晶粒５がビームスポ
ット４の径より小さい第２図（Ａ）の場合はそれぞれの
結晶粒の結晶面方位によるラマンビーク強度依存性が、
ビーム径が大きいため平均化され、ピーク強度の変化は
小さい。また、試料からの出射光の偏光角度を９０度変
えて測定を行っても同様のう７ンビ一ク強度変化が得ら
れる。The second factor is the Raman scattering peak intensity obtained when rotating and irradiating samples with different crystal grain sizes, with the vertical axis representing the scanning distance or rotation angle, and the horizontal axis representing the scanning distance or rotation angle. (A) and (B) show cases where the spot beam diameter is large and small, respectively. In the case of FIG. 2(A) where the crystal grain 5 is smaller than the diameter of the beam spot 4, the dependence of the Raman peak intensity on the crystal plane orientation of each crystal grain is as follows.
Since the beam diameter is large, it is averaged and the change in peak intensity is small. Further, even if the measurement is performed by changing the polarization angle of the light emitted from the sample by 90 degrees, a similar change in intensity can be obtained.
第２図（Ｂ）は、結晶粒５とビームスポットの径がほぼ
同じかあるいはビームスポットの径つ＜結晶粒５より小
さい場合である。この場合は一つ一つの結晶の面方位が
ラマンビーク強度に影響するため、結晶内の照＃１場所
によるピーク強度の変動が大きい。理論的には、ビーム
スポットの直径が結晶粒径に対して非常に小さいと、１
＠の結晶粒内のラマンビークの強度は一定になり、多数
の結晶粒に！ＩｒＩＪをするとラマンビークの強度が階
段状に変化することが考えられるが、通常の膜製法であ
るＣＶＤ、スパッタリングなどにより作られる結晶粒径
は数ミクロンでありまたスポットビームの最小直径は現
在の技術では１ミクロン弱であるので、ラマンビークの
強度は第２図（Ｂ）に示すような鋭い変化を示す。FIG. 2(B) shows a case where the diameter of the crystal grain 5 and the beam spot are approximately the same or smaller than the diameter of the beam spot <the diameter of the crystal grain 5. In this case, since the plane orientation of each crystal affects the Raman beak intensity, the peak intensity varies greatly depending on the location of light #1 within the crystal. Theoretically, if the diameter of the beam spot is very small compared to the grain size,
The intensity of the Raman beak within the @ crystal grain becomes constant, and there are many crystal grains! When using IrIJ, the intensity of the Raman beak may change in a stepwise manner, but the crystal grain size produced by normal film manufacturing methods such as CVD and sputtering is several microns, and the minimum diameter of the spot beam is limited by current technology. Since it is a little less than 1 micron, the intensity of the Raman beak shows a sharp change as shown in FIG. 2(B).
旦第２図（Ｂ）のようなラマンビーク強度の分布を得、
次に試料からの出射光の偏光角度を９０度変λて同じ照
射場所のラマンビーク強度を測定すると、第２図（Ｂ）
とは別の分布を得ることができる。この２回の測定によ
り得られたデータに合うように非線形最小二乗法により
個々の粒子の方位を測定することができる。換言すると
、このように個々の結晶粒の方位が決定できる時はスポ
ットビームの径が結晶粒の径より小さ（なっていること
になる。Obtain the Raman beak intensity distribution as shown in Figure 2 (B).
Next, the Raman beak intensity at the same irradiation location was measured by changing the polarization angle of the light emitted from the sample by 90 degrees, as shown in Figure 2 (B).
A different distribution can be obtained. The orientation of each particle can be measured using the nonlinear least squares method to match the data obtained from these two measurements. In other words, when the orientation of each crystal grain can be determined in this way, the diameter of the spot beam is smaller than the diameter of the crystal grain.
以−ト説明したように、ビーム径を結晶粒径と関連させ
て変えることによって、試料の結晶方位と結晶粒径を評
価することができることになる。As explained above, by changing the beam diameter in relation to the crystal grain size, the crystal orientation and crystal grain size of the sample can be evaluated.
レーザーアニールなどにより結晶粒が例えば数１０μｍ
と太き（なった場合のラマンビーク強度変化の例を第３
（Ａ）、（Ｂ）図に示す。ビームスポット４の径が結
晶粒径より小さい時、一つの結晶粒内ではその強度が一
定となり、他の結晶粒とはその弾度レベルが異なる（第
３図（Ｂ）参照）、この異なるレベルは結晶方位の差異
を反映しており、各結晶の方位は測定側の偏光方向を９
０度回転させて同様にラマンビーク強度の測定を行うこ
とにより求めることができる。また、本例では数１０μ
ｍの大きいビーム径により照射を行い第３図（Ａ）のラ
マンビーク強度を得、第３図（Ａ）、（Ｂ）の対比をす
ることにより結晶粒径を知ることができる。Crystal grains are reduced to several tens of micrometers by laser annealing, etc.
The third example shows how the Raman beak intensity changes when the
Shown in (A) and (B). When the diameter of the beam spot 4 is smaller than the crystal grain size, the intensity is constant within one crystal grain, and its elasticity level is different from that of other crystal grains (see Figure 3 (B)). reflects the difference in crystal orientation, and the orientation of each crystal is 90 degrees above the polarization direction on the measurement side.
This can be determined by rotating the beam by 0 degrees and measuring the Raman beak intensity in the same manner. In addition, in this example, several tens of μ
The crystal grain size can be determined by irradiating with a large beam diameter m to obtain the Raman peak intensity shown in FIG. 3(A) and comparing FIGS. 3(A) and (B).
請求項１の方法は上記強度レベルの相違を利用して結晶
粒径を評価するものであって、粒界が強く関連する配線
材料のマイグレーション、ＡρとＳｔの粒界拡散による
コンタクト不良、ポリＳｉの結晶粒微細化による移動度
低下、リーク電流低下などを抑制するために結晶粒径の
値を製造プロセスに反映することを特徴する請求項ｌ記
載の方法では対象物の結晶粒は斉粒（粒径のそろった粒
）であると正確なすなわち狭い範囲の結晶粒径が分かる
。一方、粗粒グループと微粒グループの二つに分かれた
混粒組織の対象物では使用するビーム径が結晶粒より小
さい領域ではラマンビーク強度の変化は小さ（、大きい
領域では粒径ごとの変化が著しいので測定対象物の面内
での結晶粒のばらつきを知ることができる。また、粗粒
が数個まとまっておりかつ微粒も数個まとまっていると
きは各グループの粒径を評価することができる。The method according to claim 1 evaluates the crystal grain size by utilizing the difference in the intensity level, and is capable of evaluating the crystal grain size by using the difference in the intensity level, and is capable of evaluating the crystal grain size due to migration of wiring material that is strongly related to grain boundaries, contact failure due to grain boundary diffusion of Aρ and St, and poly-Si. In the method according to claim 1, the crystal grains of the object are uniform grains ( If the crystal grain size is uniform (grain size), it is possible to determine the accurate crystal grain size, that is, within a narrow range. On the other hand, for an object with a mixed grain structure divided into two groups, a coarse grain group and a fine grain group, the change in Raman peak intensity is small in the region where the beam diameter used is smaller than the crystal grain (but in the large region, the change for each grain size is significant). Therefore, it is possible to know the dispersion of crystal grains within the plane of the object to be measured.Also, when several coarse grains are clustered together and several fine grains are clustered together, the grain size of each group can be evaluated. .
請求項１記載の方法では個々の結晶粒の方位の測定は必
須ではなく、ラマンビーク強度変化が測定誤差以上の変
化があったことを検出して結晶粒系を求めるものである
。このように結晶方位を求めない方法は予め結晶方位が
分かつている材料について適用することが好ましい。In the method described in claim 1, it is not essential to measure the orientation of individual crystal grains, but the crystal grain system is determined by detecting that there is a change in Raman beak intensity that is greater than the measurement error. It is preferable to apply such a method that does not determine the crystal orientation to a material whose crystal orientation is known in advance.
請求項２の発明は粒径の確定後に方位を求める方法で有
り、Ｘ線回折のようにマクロの方位を求めるのではなく
、個々の結晶粒の方位を求める方法である。The invention of claim 2 is a method of determining the orientation after determining the grain size, and is a method of determining the orientation of each individual crystal grain, rather than determining the macro orientation as in X-ray diffraction.
実際の半導体素子構成多結晶材料は（１１０）（１１１
１，（１００＋などの単純な面より構成されることは少
なく、単純な次数面とより高次数の面から構成されるか
あるいは高次数面だけから構成されることが多い。この
場合は個々の結晶粒の方位を決定することにより、ビー
ムスポットが確実に結晶粒より小さいことを確定できる
ので、請求項３記載の発明を実施することが好ましい。The actual polycrystalline materials for semiconductor devices are (110) (111)
It is rarely composed of simple surfaces such as 1, (100+), and is often composed of simple and higher-order surfaces, or only high-order surfaces.In this case, individual By determining the orientation of the crystal grains, it is possible to reliably determine that the beam spot is smaller than the crystal grains, so it is preferable to carry out the invention according to claim 3.
請求項４の方法は製造工程の途中で結晶性の検査を行っ
て、例えば余りに結晶粒径が小さい材料、あるいは粒界
を介して接する結晶粒の方位が余りに違いすぎる材料に
ついては、不合格と判定して、後工程の処理を行わない
ようにする高品質デバイスの製造法である。この場合、
ウェーハに多数配列されたチップについて全数検査を行
って個々のチップを良品と不良品に分けることができる
。The method of claim 4 inspects crystallinity during the manufacturing process, and for example, materials with too small crystal grain size or materials with too different orientations of crystal grains that are in contact with each other through grain boundaries are rejected. This is a method for manufacturing high-quality devices that eliminates the need for post-process processing. in this case,
A 100% inspection of a large number of chips arranged on a wafer can be performed to separate the individual chips into good and defective chips.
１作用）
多結晶材料を測定する光７系ではラマン分光装置におけ
る入射又は反射光の偏光方向を変えることによって照射
位置を変化させずにラマンビーク強度の実験値を求める
ことができる。これを計算値と比較することによってそ
の個々の結晶粒の面方位を決定することができる（第１
〜３図（Ｂ）の場合）。一方、第１〜３図（Ａ）の場合
は、光学系を同様に回転させても各方位の強度が平均さ
れた値となり、方位を求めることはできない。(1) In the optical system 7 for measuring polycrystalline materials, the experimental value of the Raman peak intensity can be obtained without changing the irradiation position by changing the polarization direction of the incident or reflected light in the Raman spectrometer. By comparing this with the calculated value, the plane orientation of each grain can be determined (first
- In the case of Figure 3 (B)). On the other hand, in the case of FIGS. 1 to 3(A), even if the optical system is similarly rotated, the intensity in each direction becomes an average value, and the direction cannot be determined.
したがって、照射するレーザビーム径を変えることによ
り得られるラマンビーク強度変化の程度により結晶粒径
が未知の材料の粒径な知ることができる。このレーザー
ビームの径は顕微鏡の対物レンズの倍率が１００倍のと
きは〜１１１ｍ、ついで５０倍の時〜２μｍとなる。こ
れまでに半導体素子に用いられてきたポリシリコン粒径
は非常に小さいが、後述の低温で堆積したポリシリコン
をアニールしたものは、結晶化した結果μｍオーダーの
結晶粒が得られる。このような材料径に対応する第１の
ビーム径により求められるラマンビーク強度自体は結晶
方位を全く示さないが、第２のビーム径で求められるラ
マンビーク強度変化との対比により結晶粒径決定のため
に使用される。Therefore, the grain size of a material whose crystal grain size is unknown can be determined by the degree of change in Raman peak intensity obtained by changing the diameter of the irradiated laser beam. The diameter of this laser beam is approximately 111 m when the magnification of the objective lens of the microscope is 100 times, and approximately 2 μm when the magnification is 50 times. The polysilicon grains that have been used for semiconductor devices so far are very small, but polysilicon deposited at a low temperature and annealed, as described below, is crystallized to obtain crystal grains on the order of micrometers. Although the Raman beak intensity itself determined by the first beam diameter corresponding to the material diameter does not indicate the crystal orientation at all, it can be used to determine the crystal grain size by comparing it with the Raman beak intensity change determined by the second beam diameter. used.
本発明では第１のビーム径より小さい第２のビーム径で
ラマンビーク強度を求めると、第１図（Ｂ）、第２図（
Ｂ）の状態となる。したがって、結晶粒径は第１のビー
ムと第２のビーム径の中間にあることが把握できる。こ
ねらのビーム径の中間ビーム径により同様の測定を行う
ことにより、さらに結晶粒径がより狭い範囲にあること
が把握できる。In the present invention, when the Raman peak intensity is determined using a second beam diameter smaller than the first beam diameter, the results are as follows: Fig. 1 (B) and Fig. 2 (
B) will result. Therefore, it can be understood that the crystal grain size is between the first beam diameter and the second beam diameter. By performing a similar measurement using an intermediate beam diameter of Konera's beam diameter, it can be determined that the crystal grain size is in a narrower range.
対物レンズの倍率については、一般に入手可能な最高倍
率は１００倍で、このとき得られる集光結晶粒径を評価
し、次にその方位を測定し、成長条件と方位の関係など
調査することができる。Regarding the magnification of the objective lens, the highest magnification that is generally available is 100 times, and it is possible to evaluate the condensing crystal grain size obtained at this time, then measure its orientation, and investigate the relationship between growth conditions and orientation. can.
また方位を測定する場合は例えば第３図（Ａ）において
結晶５ａは（１００）、３０°回転、結晶５ｂは（９０
０）のように各結晶粒の方位を求めることができる。さ
らに回転角度の僅かな相違により結晶粒界を生じている
場合についても各結晶について回転角度を求めることが
できる。本発明方法は非破壊法であるから、全チップに
ついて全数検査を行うことができる。In addition, when measuring the orientation, for example, in FIG.
The orientation of each crystal grain can be determined as shown in 0). Further, even if a grain boundary occurs due to a slight difference in the rotation angle, the rotation angle can be determined for each crystal. Since the method of the present invention is a non-destructive method, all chips can be 100% inspected.
以下、実施例によりさらに詳しく本発明を説明する。Hereinafter, the present invention will be explained in more detail with reference to Examples.
第５図はラマン分光装置の構成図である。光源１０とし
てはアルゴンレーザ （λ＝５１４．５ｎｍ）を用いる
。レーザ光は直線偏光しており、フィルター１１を通し
て倍波などの不要成分を除（。顕微鏡１２の鏡筒に入射
されたのち、ハーフミラ−１３で試料３に垂直にさせる
。前述のように対物レンズ２によってレーザ光は集光さ
れる。試料３かも放出されたラマン敗乱光は、対物レン
ズ２を通り、ハーフミラ−１４によって出射する。この
光の中には入射さねたレーザの波長と同じレイリー光が
含まれているので、このうちラマン光のみを取り出すた
めグラントムソンプリズム１５を用いる。これによって
得られたラマン光は、その波長成分を分離するために、
モノクロメータ）６によって分光される、最後に各波長
成分の強度を調べるためにフォトマル２０に入射される
。１８はレーザー光が試料３へのどこに照射されている
か目で確認するための接眼レンズ部のミラーである。FIG. 5 is a configuration diagram of the Raman spectrometer. As the light source 10, an argon laser (λ=514.5 nm) is used. The laser beam is linearly polarized, and unnecessary components such as harmonics are removed through a filter 11. After entering the lens barrel of the microscope 12, it is made perpendicular to the sample 3 by the half mirror 13. The laser beam is focused by 2. The Raman scattered light emitted from the sample 3 passes through the objective lens 2 and is emitted by the half mirror 14. Since Rayleigh light is included, a Glan-Thompson prism 15 is used to extract only the Raman light.In order to separate the wavelength components of the Raman light obtained by this, the Glan-Thompson prism 15 is used.
The light is spectrally separated by a monochromator (monochromator) 6, and finally enters a photomultiplier 20 to examine the intensity of each wavelength component. Reference numeral 18 denotes a mirror in the eyepiece portion for visually confirming where on the sample 3 the laser beam is irradiated.
この装置に対し、試料３はパルスモータ−駆動によるＸ
−Ｙステージ１７上に置かれ、その移動はμｍ９下のピ
ッチで移動される。For this device, sample 3 is
- It is placed on the Y stage 17 and moves at a pitch of less than 9 μm.
Ｘ−Ｙステージ１７を用いて試料上を直線的に走査すれ
ば、試料３を構成している結晶粒の太きさを見積もるこ
とができるが、試料面を二次元的に走査することによっ
て、結晶粒のそれぞれの形を見積もることも可能である
。By linearly scanning the sample using the X-Y stage 17, it is possible to estimate the thickness of the crystal grains that make up the sample 3, but by scanning the sample surface two-dimensionally, It is also possible to estimate the shape of each grain.
具体的ｒ（試料としては、シリコン基板上に熱酸化膜を
６００ｎｍ形成し、その上に堆積温度４５０℃で厚さ４
００ｎｍでポリシリコンを堆積する。これを６５０℃、
３０分アニールを行ったものを用いた。この結晶粒の大
きさを、レーザービーム径を１μｍ（第２のビーム径ン
と２μｍ（第１のビーム径）で評価すると、それぞれ第
２図（Ｂ）、第２図（Ａ）のような結果が得られた。こ
の試料をライトエツチング液でエツチングしてみると結
晶粒の大きさは２１１ｍ弱、１μｍ強の間に分布してい
Ｉこ。Specifically (as a sample, a 600 nm thermal oxide film was formed on a silicon substrate, and a 450 nm thick thermal oxide film was formed on it at a deposition temperature of 450°C.
Deposit polysilicon to a thickness of 00 nm. This is heated to 650℃.
The one that had been annealed for 30 minutes was used. If the size of this crystal grain is evaluated using a laser beam diameter of 1 μm (second beam diameter) and 2 μm (first beam diameter), the results will be as shown in Figure 2 (B) and Figure 2 (A), respectively. The results were obtained. When this sample was etched with a light etching solution, the crystal grain sizes were distributed between a little less than 211 m and a little more than 1 μm.
［発明の効果１
以上説明したように、本発明によれば半導体膜中の結晶
粒の大きさを非破壊でかつ大気中で短時間に測定するこ
とができるため、製造工程中でその結晶性を評価したの
ち、再度製造ラインに戻し、所望の結晶性を有するウェ
ーハのみに後工程の処理を施すインライン評価を行うこ
とができる。このため、半導体装置の性能向上に寄与す
るところが大きい。[Advantageous Effects of the Invention 1] As explained above, according to the present invention, the size of crystal grains in a semiconductor film can be measured non-destructively in the atmosphere in a short time, so that the crystallinity can be measured during the manufacturing process. After evaluating the wafer, it is possible to perform an in-line evaluation in which the wafer is returned to the production line and post-processing is performed only on wafers having the desired crystallinity. Therefore, it greatly contributes to improving the performance of semiconductor devices.
さらに、本発明では多結晶材料の粒径とともに個々の結
晶の方位を測定することができるので、測定結果とプロ
セス条件の関連を検討し、方位差が少ない単結晶に近い
材料を作製するために本発明法は有意義である。Furthermore, in the present invention, it is possible to measure the grain size of polycrystalline materials as well as the orientation of individual crystals, so the relationship between measurement results and process conditions can be studied to create materials close to single crystals with little difference in orientation. The method of the present invention is significant.
第１図（Ａ）、第１図（Ｂ）はそれぞれ第１のビーム径
、第２のビーム径のビームを対象物に当てラマン敗乱光
を放出させる図、
第２図（Ａ）、第２図（Ｂ）はそれぞれ第１のビーム径
、第２のビーム径でラマン敗乱光を放出させた場合のラ
マン散乱ビーク強度の変化を示す図、
第３図（Ａ）、第３図（Ｂ）は第２図より大きい結晶粒
についての第２図（Ａ）、第２図（Ｂ）と同様の図、
第４図（Ａ）、（Ｂ）、（Ｃ）はそれぞれ（１００）、
（１１０）、（１１１１面から放出されるラマン散乱
ピークの強度を示す図、
第５図はラマン分光装置の図である。
１−レーザ光、２一対物レンズ、３−試料、５−結晶粒
、ｌ〇−光源、１１−フィルター１３−ハーフミラ−
１）−下１′□大シ１−一一へ−Ｕ
□
こ−ムス丁汁４ヘー−，０
ｒ−〜−−−４二−ムスｉ′ｉ１°７ト、杼晶［５
＝２７ノアｒマ古Ｌゴ号ミＨθ）寞イヒ第３図（Ａ）
フン１ノ歌古Ｌ’Ａ＃ 支イし
第３ ｒＸＪ（Ｂ）
第
凶（Ａ）
第
区ＣＢ）Figures 1 (A) and 1 (B) are diagrams in which beams with a first beam diameter and a second beam diameter are applied to an object to emit Raman scattered light, respectively. Figure 2 (B) is a diagram showing the change in Raman scattering peak intensity when Raman scattered light is emitted with the first beam diameter and the second beam diameter, Figure 3 (A), Figure 3 ( B) is a diagram similar to Figure 2 (A) and Figure 2 (B) for crystal grains larger than Figure 2. Figure 4 (A), (B), and (C) are (100), respectively.
(110), (A diagram showing the intensity of the Raman scattering peak emitted from the 1111 plane, Figure 5 is a diagram of the Raman spectrometer. 1-Laser light, 2-Objective lens, 3-Sample, 5-Crystal grain , l〇-Light source, 11-Filter 13-Half mirror- 1)-Lower 1'□ Large size 1-11-U □ Komus clove soup 4he-,0 r-～---42-mus i′i1°7to, Shutaki [5 = 27 Noah rma old Lgo issue Hθ) Evil (A) Section CB)
Claims (1)
ビーム径を有するレーザービームで走査し、ラマン散乱
ピークの強度が前記一表面で変化する第１の強度変化を
求め、第１のビーム径より小さい第２のビーム径を有す
るレーザービームによる走査を行ってラマン散乱ピーク
の強度が前記表面で変化する第２の強度変化を求め、第
１の強度変化と第２の強度変化を比較し、ラマン分光法
による測定精度以上の差があったときに、前記多結晶材
料の結晶粒径が第１のビーム径より小でかつ第２のビー
ム径より大であると確定することを特徴とする半導体素
子構成材料の評価方法。 ２、結晶粒径の確定後に第１のビーム径とほぼ等しいか
あるいは第１のビーム径より小さい第３のビーム径を有
するレーザービームにより多結晶材料の結晶の方位を測
定することを特徴とする請求項１記載の半導体素子構成
材料の評価方法。 ３、レーザービームを多結晶材料に対して相対的に回転
させてラマン散乱ピークを求め、また第２のビーム径に
よる走査を異なる偏光角度で２回行って、ラマン散乱ピ
ークの強度より各結晶粒の方位を測定し、粒径と結晶粒
の方位を同時に求めることを特徴とする請求項１記載の
半導体素子構成材料の評価方法。 ４、半導体素子の製造工程の途中において、請求項１に
よる対象物の結晶粒径の確定、または請求項２または３
による結晶粒径の確定ならびに方位の測定を行い、所望
の結晶粒径または方位が得られた対象物について後工程
の処理を施すことを特徴とする半導体素子構成材料の評
価方法。 ５、前記ラマン分光法において、倍率が５０倍以上の対
物レンズを備えた顕微鏡を使用することを特徴とする請
求項１から４までの何れか１項記載の半導体素子構成材
料の評価方法。[Claims] 1. A first intensity change in which one surface of a polycrystalline material constituting a semiconductor element is scanned with a laser beam having a first beam diameter, and the intensity of a Raman scattering peak changes on the one surface. is determined, a second intensity change in which the intensity of the Raman scattering peak changes on the surface is determined by scanning with a laser beam having a second beam diameter smaller than the first beam diameter, and the first intensity change and the second intensity change are determined. Compare the intensity changes of 2, and if there is a difference greater than the measurement accuracy by Raman spectroscopy, the crystal grain size of the polycrystalline material is smaller than the first beam diameter and larger than the second beam diameter. 1. A method for evaluating semiconductor element constituent materials, characterized in that it is determined that: 2. After determining the crystal grain size, the crystal orientation of the polycrystalline material is measured using a laser beam having a third beam diameter that is approximately equal to or smaller than the first beam diameter. A method for evaluating a semiconductor element constituent material according to claim 1. 3. Obtain the Raman scattering peak by rotating the laser beam relative to the polycrystalline material, and scan with the second beam diameter twice at different polarization angles to determine each crystal grain from the intensity of the Raman scattering peak. 2. The method for evaluating a material constituting a semiconductor element according to claim 1, characterized in that the grain size and the orientation of the crystal grains are simultaneously determined by measuring the orientation of the crystal grain. 4. Determining the crystal grain size of the object according to claim 1, or claim 2 or 3 during the manufacturing process of a semiconductor device.
1. A method for evaluating materials constituting a semiconductor element, the method comprising: determining the crystal grain size and measuring the orientation; and performing post-processing on the object from which the desired crystal grain size or orientation has been obtained. 5. The method for evaluating semiconductor element constituent materials according to any one of claims 1 to 4, wherein a microscope equipped with an objective lens having a magnification of 50 times or more is used in the Raman spectroscopy.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15220190A JPH0443661A (en) | 1990-06-11 | 1990-06-11 | Evaluation method of constituent material for semiconductor element |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15220190A JPH0443661A (en) | 1990-06-11 | 1990-06-11 | Evaluation method of constituent material for semiconductor element |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0443661A true JPH0443661A (en) | 1992-02-13 |
Family
ID=15535271
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP15220190A Pending JPH0443661A (en) | 1990-06-11 | 1990-06-11 | Evaluation method of constituent material for semiconductor element |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0443661A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH08330373A (en) * | 1995-06-01 | 1996-12-13 | Nec Corp | Evaluation of polycrystalline material |
| US6411906B1 (en) | 1998-02-06 | 2002-06-25 | Kabushiki Kaisha Toshiba | Method and system for inspecting polycrystalline semiconductor film |
| JP2021531469A (en) * | 2018-07-25 | 2021-11-18 | ノヴァ リミテッドNova Ltd | Optical technology for material characterization |
-
1990
- 1990-06-11 JP JP15220190A patent/JPH0443661A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH08330373A (en) * | 1995-06-01 | 1996-12-13 | Nec Corp | Evaluation of polycrystalline material |
| US6411906B1 (en) | 1998-02-06 | 2002-06-25 | Kabushiki Kaisha Toshiba | Method and system for inspecting polycrystalline semiconductor film |
| JP2021531469A (en) * | 2018-07-25 | 2021-11-18 | ノヴァ リミテッドNova Ltd | Optical technology for material characterization |
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