JP2001140058A - Method for estimating thin film thickness distribution and optical characteristic distribution - Google Patents
Method for estimating thin film thickness distribution and optical characteristic distributionInfo
- Publication number
- JP2001140058A JP2001140058A JP32483199A JP32483199A JP2001140058A JP 2001140058 A JP2001140058 A JP 2001140058A JP 32483199 A JP32483199 A JP 32483199A JP 32483199 A JP32483199 A JP 32483199A JP 2001140058 A JP2001140058 A JP 2001140058A
- Authority
- JP
- Japan
- Prior art keywords
- film thickness
- substrate
- thickness distribution
- evaporation source
- distribution
- 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
Landscapes
- Physical Vapour Deposition (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、真空蒸着法により
基板上に形成される薄膜の膜厚分布を、更には光学特性
の分布を予測する方法に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for predicting a film thickness distribution of a thin film formed on a substrate by a vacuum evaporation method, and further, a distribution of optical characteristics.
【０００２】[0002]
【従来の技術】真空蒸着法で基板上に薄膜を形成する場
合、一般に基板上に形成される薄膜の膜厚分布は均一で
はない。膜厚分布を均一にし、均一な光学特性を有する
光学薄膜を形成するために、大型真空蒸着装置は、例え
ば、図５に示すように蒸発源と基板との間に蒸着粒子を
遮蔽する遮蔽板１０６を配置している。しかし基板形状
（図５には凸面が示されている）には平面ばかりではな
く凹面、凸面があり、基板の直径、曲率半径も様々であ
る。このような多様な形状の基板上に均一な光学特性を
有する光学薄膜を形成するためには、基板上に形成され
る薄膜の膜厚分布を正確に予測し、基板上の膜厚が均一
になるように、異なる形状の基板毎に遮蔽板１０６の形
状を最適化することが必要である。2. Description of the Related Art When a thin film is formed on a substrate by a vacuum deposition method, generally, the film thickness distribution of the thin film formed on the substrate is not uniform. In order to form an optical thin film having uniform optical characteristics and a uniform film thickness distribution, a large-sized vacuum vapor deposition apparatus includes, for example, a shielding plate for shielding vapor deposition particles between an evaporation source and a substrate as shown in FIG. 106 are arranged. However, the substrate shape (the convex surface is shown in FIG. 5) has not only a flat surface but also a concave surface and a convex surface, and the diameter and the radius of curvature of the substrate are various. In order to form an optical thin film having uniform optical characteristics on a substrate having such various shapes, it is necessary to accurately predict the film thickness distribution of the thin film formed on the substrate and to make the film thickness on the substrate uniform. Therefore, it is necessary to optimize the shape of the shielding plate 106 for each substrate having a different shape.
【０００３】従来、真空蒸着法により形成した薄膜の基
板上の膜厚分布は、微小平面蒸発源モデルを基にした下
式により予測していた。 ｄ∝cos L θcos M φ／ｒN （式１） ここで、θ、φ、ｒは、図８に示すように、 θ：基板に対する蒸気入射角度、 φ：蒸気の放射角度、 ｒ：蒸発源と基板面との距離 である。Heretofore, the film thickness distribution of a thin film formed by a vacuum evaporation method on a substrate has been predicted by the following equation based on a small flat evaporation source model. d∝cos L θcos M φ / r N (Equation 1) where θ, φ, and r are, as shown in FIG. 8, θ: vapor incident angle to the substrate, φ: vapor radiation angle, r: evaporation source And the distance from the substrate surface.
【０００４】ここで、Ｌ、Ｍ、Ｎは、使用する個々の真
空蒸着装置固有な定数値である。これら定数値Ｌ、Ｍ、
Ｎは、実験的に膜厚分布を測定し、Ｌ、Ｍ、Ｎをフィッ
ティングパラメータとして、式１をその膜厚分布結果に
合わせこむ、フィッティングにより求められる。具体的
には、例えばパラメータＬを決定するために、変数φ、
ｒを一定に保ち、θを変化させながら成膜を行い、θと
膜厚の関係を測定により求める。このθと膜厚の関係に
式１をフィッティングさせることによりＬを求める。フ
ィッティングには例えば最小二乗法が用いられる。以上
のような方法でパラメータＭ、パラメータＮを次々と決
定していくのである。[0004] Here, L, M, and N are constant values specific to each of the vacuum evaporation apparatuses used. These constant values L, M,
N is obtained by fitting by measuring the film thickness distribution experimentally and using L, M, and N as fitting parameters and fitting Equation 1 to the film thickness distribution result. Specifically, for example, in order to determine the parameter L, the variables φ,
The film is formed while changing r while keeping r constant, and the relationship between θ and the film thickness is determined by measurement. L is determined by fitting Equation 1 to the relationship between θ and the film thickness. For the fitting, for example, the least square method is used. The parameters M and N are determined one after another by the above method.
【０００５】以上のようにして求められた定数値Ｌ、
Ｍ、Ｎで決定された式１により膜厚を計算することによ
って膜厚分布を予測し、更に、所定の基板上で膜厚分布
を均一化するよう、異なる形状の基板毎に遮蔽板の形状
を決定し、補正された膜厚分布を予測していたのであ
る。[0005] The constant value L obtained as described above,
The thickness distribution is predicted by calculating the thickness according to Equation 1 determined by M and N, and furthermore, the shape of the shielding plate is set for each of the substrates having different shapes so as to make the thickness distribution uniform on a predetermined substrate. Was determined, and the corrected film thickness distribution was predicted.
【０００６】[0006]
【発明が解決しようとする課題】しかしながら従来の膜
厚分布予測方法はＬ、Ｍ、Ｎのフィッティングパラメー
タを決定するために、数十回に及ぶ実験を行わなくては
ならず、膨大なコストと所要時間を要していた。更に、
従来の膜厚分布予測方法は、大型の真空蒸着装置の場合
のように蒸発源と基板、および蒸発源と遮蔽板との距離
が離れていて、蒸発源を微小平面蒸発源として見做すこ
とができる場合には精度良く予測することができた。し
かし蒸発源と基板、もしくは蒸発源と遮蔽板の距離が比
較的近く、蒸発源を微少平面蒸発源として見做すことが
できない場合は、微小平面蒸発源モデルを基にした従来
方法では膜厚分布を予測することが困難であった。However, the conventional method for estimating the film thickness distribution has to perform dozens of experiments to determine the fitting parameters of L, M, and N, resulting in enormous cost and cost. It took time. Furthermore,
The conventional method for estimating the film thickness distribution assumes that the distance between the evaporation source and the substrate and the distance between the evaporation source and the shielding plate are large, as in the case of a large vacuum evaporation system, and that the evaporation source is regarded as a small planar evaporation source. Could be predicted with high accuracy. However, when the distance between the evaporation source and the substrate or the distance between the evaporation source and the shielding plate is relatively short and the evaporation source cannot be regarded as a minute plane evaporation source, the conventional method based on the minute plane evaporation source model uses the film thickness. It was difficult to predict the distribution.
【０００７】更に、従来の、Ｌ、Ｍ、Ｎをフィッティン
グパラメータとして、式１を膜厚分布の測定結果に合わ
せこむことにより得られた式１により膜厚分布を予測す
る方法は物理的根拠に基づかず、実験的に得られた結果
を基にしているために、実験を行なった範囲外への適用
が効かず、適用範囲が狭かった。また、一般に知られて
いる面蒸発源モデルを起点とする膜厚分布予測方法は計
算が煩雑であり、汎用性が乏しかった。Further, the conventional method of predicting the film thickness distribution by the equation 1 obtained by fitting the equation 1 to the measurement result of the film thickness distribution using L, M, and N as fitting parameters is based on physical grounds. It was not based, but based on experimentally obtained results, so application outside the range in which the experiment was performed was not effective and the application range was narrow. In addition, the generally known method for predicting the film thickness distribution starting from a surface evaporation source model is complicated in calculation, and is poor in versatility.
【０００８】[0008]
【課題を解決するための手段】前記問題点を解決するた
めに、本発明は第一に、真空中で、蒸発源の物質を気化
させ、その蒸気を基板上に堆積させる、真空蒸着法によ
り基板上に形成される薄膜の膜厚分布を予測する方法で
あって、前記蒸発源を複数の微小平面蒸発源によりモデ
ル化する段階を具えることを特徴とする膜厚分布予測方
法を提供する。In order to solve the above problems, the present invention firstly provides a vacuum evaporation method in which a substance of an evaporation source is vaporized in a vacuum and the vapor is deposited on a substrate. A method for predicting a film thickness distribution of a thin film formed on a substrate, comprising a step of modeling the evaporation source by a plurality of minute planar evaporation sources. .
【０００９】第二に、更に、前記各微小平面蒸発源によ
り前記基板上に形成される薄膜の膜厚（ｄ）の分布を、 ｄ∝Ｗcos θcos φ／ｒ2 ここで、Ｗ：各微小平面蒸発源の重み θ：基板に対する蒸気の入射角度 φ：蒸気の放射角度 ｒ：蒸発源と基板面との距離 なる式で算出する段階を具えることを特徴とする請求項
１記載の膜厚分布予測方法を提供する。Second, the distribution of the film thickness (d) of the thin film formed on the substrate by each of the minute plane evaporation sources is represented by d∝Wcos θcos φ / r 2 where W: each minute plane 2. The film thickness distribution according to claim 1, wherein the weight of the evaporation source θ: the incident angle of the vapor on the substrate φ: the radiation angle of the vapor r: the distance between the evaporation source and the substrate surface Provide a forecasting method.
【００１０】第三に、前記微小平面蒸発源の数が５個以
上であることを特徴とする請求項１、２何れか１項記載
の膜厚分布予測方法を提供する。第四に、前記複数の微
小平面蒸発源が、前記蒸発源の掘れ跡を模して配置され
ることを特徴とする請求項１〜３何れか１項記載の膜厚
分布予測方法を提供する。Thirdly, there is provided a method for predicting a film thickness distribution according to any one of claims 1 and 2, wherein the number of the minute flat evaporation sources is five or more. Fourthly, there is provided a method for predicting a film thickness distribution according to any one of claims 1 to 3, wherein the plurality of minute plane evaporation sources are arranged so as to imitate a digging mark of the evaporation source. .
【００１１】第五に、更に、前記蒸発源と前記基板との
間に適当な遮蔽板を配置することにより膜厚分布を所定
の分布に計算上補正する段階を具えることを特徴とする
請求項１〜４何れか１項記載の膜厚分布予測方法を提供
する。第六に、請求項１〜５何れか１項記載の膜厚分布
予測方法に記載された段階に加えて更に薄膜の光学特性
の分布を計算する段階を具えることを特徴とする光学特
性分布予測方法を提供する。Fifth, the method further comprises a step of calculating a film thickness distribution to a predetermined distribution by arranging an appropriate shielding plate between the evaporation source and the substrate. Item 5 provides a film thickness distribution prediction method according to any one of Items 1 to 4. Sixthly, in addition to the steps described in the film thickness distribution prediction method according to any one of claims 1 to 5, a step of calculating a distribution of optical properties of the thin film is further provided. Provide a forecasting method.
【００１２】[0012]
【発明の実施形態】本発明の実施形態を以下に示す。な
お、本実施形態では蒸発源の試料（物質）の気化を物質
の電子線照射による加熱により行なった場合について説
明しているが、この他に抵抗加熱により行なっても、高
周波加熱により行なっても良い。更に試料の加熱による
気化のみならず、比較的低圧力で行なわれるイオンビー
ムスパッタリング、等による物質の気化を行なっても良
い。本発明には、蒸発源と基板との距離が平均自由行程
よりも短い条件下で成膜が行なわれる全ての気化方法が
含まれる。Embodiments of the present invention will be described below. In the present embodiment, the case where the evaporation source sample (substance) is vaporized by heating the substance by electron beam irradiation is described. However, the vaporization may be performed by resistance heating or high frequency heating. good. Further, in addition to the vaporization by heating the sample, the substance may be vaporized by ion beam sputtering performed at a relatively low pressure. The present invention includes all vaporization methods in which a film is formed under the condition that the distance between the evaporation source and the substrate is shorter than the mean free path.
【００１３】電子線加熱による真空蒸着法による薄膜形
成において蒸発試料に電子線照射を行うと、蒸発試料は
通常は溶融または昇華し、電子線の照射部分の試料が気
化し蒸気として放射する。気化の進行につれて、この蒸
発試料が気化した部分は下方に抉れ、蒸発試料の照射面
に一定の形状の掘れ跡を形成する。この掘れ跡の形状
（以下溶融形状と呼ぶ）は、試料及び蒸発条件が決まれ
ば一定の形状を取り、通常は、上方から見て円形とな
る。具体例として、電子線加熱の真空蒸着装置を真空に
排気し、蒸発試料としてのフッ化マグネシウム試料に１
８０度偏向させた電子線を照射する実験を繰り返し行な
ったところ、フッ化マグネシウム試料の溶融形状は、一
定の照射条件下では常に直径２０ｍｍの円形となること
がわかった。When an evaporating sample is irradiated with an electron beam in forming a thin film by a vacuum evaporation method using electron beam heating, the evaporating sample is usually melted or sublimated, and the sample irradiated with the electron beam is vaporized and emitted as vapor. As the vaporization progresses, the vaporized portion of the vaporized sample is digged downward to form a dug trace of a certain shape on the irradiation surface of the vaporized sample. The shape of the digging mark (hereinafter, referred to as a melting shape) takes a certain shape if the sample and the evaporation conditions are determined, and is usually circular when viewed from above. As a specific example, the vacuum evaporation apparatus for electron beam heating is evacuated to a vacuum, and a magnesium fluoride sample as an evaporation sample is charged with 1%.
When the experiment of irradiating the electron beam deflected by 80 degrees was repeated, it was found that the molten shape of the magnesium fluoride sample was always a circle having a diameter of 20 mm under a constant irradiation condition.
【００１４】理解を容易にするために、具体的な上記溶
融形状を用いて以下の説明を行なうが、本発明はこの形
状に限定されるものではない。本発明では、先ず、蒸発
源を図１に示すように、対角線長が２０ｍｍの正方形の
各頂点と中心に配置された計５個の微小平面蒸発源にモ
デル化する。次に、真空槽中に、少なくとも、所望の膜
厚分布測定範囲をカバーする平面基板をセットし、真空
に排気し、前記蒸発源を用いて蒸発試料を実際に蒸発さ
せ、遮蔽板を入れない状態で基板上に薄膜を堆積させて
形成する。薄膜形成時の圧力は好ましくは基板と蒸発源
間距離よりも平均自由行程が長くなる圧力以下であり、
通常は１×１０-2Ｐａ以下とする。また、成膜時の加速
電圧とビーム電流は溶融形状に影響を与えるので、これ
らは、実験、生産を通じて所定の条件に保持される。成
膜後、平面基板上の各位置での膜厚を測定することによ
り膜厚分布を測定する。この成膜と測定は必要な測定精
度に応じて通常は数回繰り返され、その結果は実験誤差
の影響を減らすために通常平均される。In order to facilitate understanding, the following description will be made using the above-mentioned specific molten shape, but the present invention is not limited to this shape. In the present invention, first, as shown in FIG. 1, the evaporation sources are modeled as a total of five micro-plane evaporation sources arranged at the vertices and the center of a square having a diagonal length of 20 mm. Next, in a vacuum chamber, at least a flat substrate covering a desired film thickness distribution measurement range is set, evacuated to vacuum, and the evaporation sample is actually evaporated using the evaporation source, and the shielding plate is not inserted. In this state, a thin film is deposited and formed on a substrate. The pressure at the time of forming the thin film is preferably not more than the pressure at which the mean free path is longer than the distance between the substrate and the evaporation source,
Usually, the pressure is 1 × 10 −2 Pa or less. In addition, since the acceleration voltage and beam current at the time of film formation affect the melted shape, these are maintained under predetermined conditions through experiments and production. After the film formation, the film thickness distribution is measured by measuring the film thickness at each position on the flat substrate. This deposition and measurement is usually repeated several times depending on the required measurement accuracy, and the results are usually averaged to reduce the effects of experimental errors.
【００１５】次に、前にモデル化した５個の微小平面蒸
発源にて上記実験に用いた平面基板と同一形状の平面基
板上の膜厚分布を計算する。計算は以下の式２により行
われる。 ｄ∝Ｗcos θcos φ／ｒ2 （式２） ここで、θ、φ、ｒは、図８に示すように、 Ｗ：重み θ：基板に対する蒸気入射角度 φ：蒸気の放射角度 ｒ：蒸発源と基板面との距離 である。Next, the film thickness distribution on the flat substrate having the same shape as the flat substrate used in the above experiment is calculated using the five minute flat evaporation sources modeled before. The calculation is performed according to Equation 2 below. d∝Wcos θcos φ / r 2 (Equation 2) Here, θ, φ, and r are, as shown in FIG. 8, W: weight θ: vapor incident angle to the substrate φ: vapor radiation angle r: evaporation source This is the distance from the substrate surface.
【００１６】次に、計算により求められた膜厚分布と実
験で求められた膜厚分布とが最も良くフィッティングす
るように各微小平面蒸発源の重みを調整する。フィッテ
ィングの結果、中央の微小平面蒸発源の重みは他の４個
の頂点位置の蒸発源の重みの２倍となった。このように
して電子線照射による蒸発源モデルが構築された。Next, the weight of each minute flat evaporation source is adjusted so that the film thickness distribution obtained by calculation and the film thickness distribution obtained by experiment are best fitted. As a result of the fitting, the weight of the evaporation source at the center minute plane was twice the weight of the evaporation sources at the other four apexes. Thus, an evaporation source model by electron beam irradiation was constructed.
【００１７】この蒸発源モデルを用い、以下の実施例に
て基板上の膜厚分布を予測する。以上の説明では、蒸発
試料がフッ化マグネシウムの場合を説明したが、本モデ
ルは他の物質に対しても適用できることは言うまでもな
い。本説明では蒸発源を５つの微小平面蒸発源により蒸
発源モデルを構築したが、より正確な膜厚予測を必要と
するときは微小平面蒸発源の数を増やすことにより容易
に行えることは言うまでもない。Using this evaporation source model, a film thickness distribution on a substrate is predicted in the following embodiments. In the above description, the case where the evaporated sample is magnesium fluoride has been described, but it goes without saying that this model can be applied to other substances. In the present description, the evaporation source is constructed with the evaporation source model using five minute plane evaporation sources. However, when more accurate film thickness prediction is required, it can be easily performed by increasing the number of minute plane evaporation sources. .
【００１８】また、蒸発源の溶融形状は、薄膜形成の進
行に伴い若干変化する。膜厚分布の測定精度をより高め
るために、必要に応じて、時間と共に変化する溶融形状
に対応し、時間と共に変化する蒸発源モデルを用いるこ
ともある。次に、以上のようにして構築された蒸発源モ
デルを用い、所望の形状の基板上の膜厚分布を予測す
る。Further, the molten shape of the evaporation source slightly changes with the progress of thin film formation. In order to further improve the measurement accuracy of the film thickness distribution, an evaporation source model that changes with time, which corresponds to a molten shape that changes with time, may be used as necessary. Next, using the evaporation source model constructed as described above, a film thickness distribution on a substrate having a desired shape is predicted.
【００１９】更に、本発明は前記所望の形状の基板上の
膜厚分布が予測された後に、この膜厚分布を均一化する
ためにまたは所定の膜厚分布を得るために、調整された
形状の遮蔽板が蒸発源と基板との間に配置される。この
遮蔽板としては図３で示されたような、大円と小円とを
長方形を介して連結した形状の開口部を有するものが好
ましく用いられる。大円は蒸発源に対応した位置に配置
されている。この開口部の寸法を適当に調節して所定の
膜厚分布の計算値を得ることを目的のものとするのであ
る。この遮蔽板の技術は特願平１１−００１１５２に詳
しく開示されている。遮蔽板としては、以上のようなタ
イプのものに限らず、図７の従来例の遮蔽板のタイプの
ものでも良く、他の適当な、蒸発源からの放射蒸気の分
布を適当に補正するものならば特にタイプは限定されな
い。 ［実施例］以上のようにして構築された蒸発源モデルを
用いて、図２で示される真空蒸着装置により基板上に形
成される薄膜の膜厚分布の予測を実際に行った。Further, according to the present invention, after the film thickness distribution on the substrate having the desired shape is predicted, the shape is adjusted to uniform the film thickness distribution or to obtain a predetermined film thickness distribution. Is disposed between the evaporation source and the substrate. As the shield plate, a shield plate having an opening formed by connecting a great circle and a small circle via a rectangle as shown in FIG. 3 is preferably used. The great circle is located at a position corresponding to the evaporation source. The purpose is to appropriately adjust the size of the opening to obtain a predetermined calculated value of the film thickness distribution. The technique of this shielding plate is disclosed in detail in Japanese Patent Application No. 11-001152. The shielding plate is not limited to the above type, but may be the type of the shielding plate of the conventional example shown in FIG. 7, and any other appropriate one that appropriately corrects the distribution of the radiated vapor from the evaporation source. Then, the type is not particularly limited. EXAMPLE Using the evaporation source model constructed as described above, the film thickness distribution of a thin film formed on a substrate by the vacuum evaporation apparatus shown in FIG. 2 was actually predicted.
【００２０】図２にて１は真空槽、２は蒸発源ユニッ
ト、３は遮蔽板、４は基板（レンズ）、５は基板ホル
ダ、Ｃａは交点軸、Ｃｂは自転軸、６は気化蒸気、７は
開口である。基板４は基板ホルダ５に保持されており、
基板ホルダ５は、基板４が自転軸Ｃｂの回りに自転しな
がら公転軸Ｃａの回りに公転するように構成されてい
る。公転軸Ｃａと自転軸Ｃｂとの軸間距離は３３８ｍｍ
である。In FIG. 2, 1 is a vacuum chamber, 2 is an evaporation source unit, 3 is a shielding plate, 4 is a substrate (lens), 5 is a substrate holder, Ca is an intersection axis, Cb is a rotation axis, 6 is vaporized steam, 7 is an opening. The substrate 4 is held by a substrate holder 5,
The substrate holder 5 is configured so that the substrate 4 revolves around the revolving axis Ca while revolving about the revolving axis Cb. The center distance between the revolution axis Ca and the rotation axis Cb is 338 mm
It is.
【００２１】蒸発源ユニット２は、基板４の自転軸の公
転軌道上の所定の点の１０００ｍｍ下方に配置されてい
る。蒸発試料は蒸発源ユニット２に装填される。蒸発源
は蒸発源ユニット２の中央にセットされ、ここでは蒸発
源の高さは蒸発源ユニット２の高さと同一に調整されて
いる。蒸発試料の加熱による蒸発は真空槽１内の蒸発試
料近傍に配置された電子銃（図示されず）から放射され
た電子線により行なわれる。また蒸発源ユニットの上方
１６０ｍｍには開口部７を持つ遮蔽板３が配置されてい
る。遮蔽板３の形状は図３に示すとおりであり、大円の
半径６０ｍｍ、小円の半径３０ｍｍ、大円と小円とを連
結する長方形の長さを５５．５ｍｍ、幅３０ｍｍとし
た。The evaporation source unit 2 is arranged 1000 mm below a predetermined point on the orbit of the rotation axis of the substrate 4. The evaporated sample is loaded into the evaporation source unit 2. The evaporation source is set at the center of the evaporation source unit 2, where the height of the evaporation source is adjusted to be the same as the height of the evaporation source unit 2. The evaporation of the evaporation sample by heating is performed by an electron beam emitted from an electron gun (not shown) disposed near the evaporation sample in the vacuum chamber 1. Further, a shielding plate 3 having an opening 7 is disposed 160 mm above the evaporation source unit. The shape of the shielding plate 3 was as shown in FIG. 3, and the radius of the great circle was 60 mm, the radius of the small circle was 30 mm, the length of the rectangle connecting the great circle and the small circle was 55.5 mm, and the width was 30 mm.
【００２２】なお、薄膜形成時の真空槽内の圧力は１×
１０-3Ｐａ以下とした。また本実施例では膜厚分布予測
の対象の基板として、曲率半径１６５ｍｍ、有効径２５
０ｍｍの凸レンズ形状の基板を選んだ。上記形状の基板
上の膜厚分布の予想は以下のようにして行なった。図２
における、自公転をする基板ホルダー５に保持された基
板４の表面上の任意の点が、蒸発源ユニット２にセット
された蒸発源に対して一定の位置関係にあるとき、その
点に於ける１つの微小平面蒸発源による膜厚は、式２に
よって求められる。計算に当たって蒸着は所定の単位時
間行なわれるものと仮定する。最初の点と基板上の同一
半径方向にある他の任意な点についても同様に膜厚の計
算を行えば、基板上のこの他の点での膜厚も求められ
る。このようにして、基板の半径方向に所定の間隔で複
数点の膜厚を計算すれば、基板上の半径方向の膜厚分布
が得られる。The pressure in the vacuum chamber when forming a thin film is 1 ×
It was set to 10 −3 Pa or less. Further, in this embodiment, as the target substrate of the film thickness distribution prediction, the radius of curvature is 165 mm and the effective diameter is 25.
A 0 mm convex lens shaped substrate was selected. The film thickness distribution on the substrate having the above shape was estimated as follows. FIG.
When an arbitrary point on the surface of the substrate 4 held by the orbiting substrate holder 5 is in a fixed positional relationship with respect to the evaporation source set in the evaporation source unit 2, The film thickness by one minute flat evaporation source is obtained by Expression 2. In the calculation, it is assumed that deposition is performed for a predetermined unit time. If the film thickness is similarly calculated for the initial point and other arbitrary points on the substrate in the same radial direction, the film thickness at other points on the substrate can also be obtained. By calculating the film thickness at a plurality of points at predetermined intervals in the radial direction of the substrate in this manner, a radial film thickness distribution on the substrate can be obtained.
【００２３】本実施例では微小平面蒸発源を５つ配して
いるのでそれぞれの蒸発源に対して同様の計算を行い、
各蒸発源に対して膜厚分布を計算する。このとき、蒸発
源モデルの中心位置にある微小平面蒸発源からの放射強
度は頂点位置にある他の微小平面蒸発源の２倍（Ｗ＝
２）とする。この各微小平面蒸発源からの膜厚分布の５
個所についての総和を取ることにより、基板と蒸発源が
一定の位置関係にあるときの本発明の蒸発源モデルによ
る膜厚分布が計算される。In this embodiment, since five small flat evaporation sources are arranged, the same calculation is performed for each evaporation source.
The film thickness distribution is calculated for each evaporation source. At this time, the radiation intensity from the micro-flat evaporation source at the center position of the evaporation source model is twice (W =
2). 5 of the film thickness distribution from each of these minute planar evaporation sources
By taking the sum of the locations, the film thickness distribution by the evaporation source model of the present invention when the substrate and the evaporation source are in a fixed positional relationship is calculated.
【００２４】次に基板の位置を、所定の自転速度、公転
速度で決定される自公転軌道に従い移動させる。ここで
は、公転速度７ｒｐｍ、自転速度１８ｒｐｍで回転を行
なった。移動に伴い、基板上の半径上の各点の位置は蒸
発源に対して変化して行く。初期位置と自公転開始から
の時間（経過時間）が決まれば、所定の経過時間に於け
る本発明の蒸発源モデルによる膜厚分布が計算される。
但し、この計算に於いて、この所定の経過時間に於いて
基板は蒸発源に対して一定の固定した位置関係にあるも
のと仮定して、前記所定の単位時間だけ成膜されるとし
て計算される。Next, the position of the substrate is moved according to a revolution orbit determined by a predetermined rotation speed and revolution speed. Here, rotation was performed at a revolving speed of 7 rpm and a rotation speed of 18 rpm. With the movement, the position of each point on the radius on the substrate changes with respect to the evaporation source. When the initial position and the time (elapsed time) from the start of the revolution, the film thickness distribution at the predetermined elapsed time by the evaporation source model of the present invention is calculated.
However, in this calculation, the substrate is assumed to be in a fixed fixed positional relationship with respect to the evaporation source during the predetermined elapsed time, and the calculation is performed assuming that the film is formed for the predetermined unit time. You.
【００２５】前段の計算を、公転回数で約６周の間、所
定の時間間隔毎に繰り返し行うと、各所定の時間間隔毎
の膜厚分布が求められる。この各所定の時間間隔毎の膜
厚分布を全て加算することにより、半径方向の膜厚分布
が計算される。自転速度は公転速度よりも大きく、且つ
公転運動と自転運動が相互に干渉しないように設定され
ているので、このようにして計算された半径方向の膜厚
分布は、基板上の異なる全ての半径方向にて同じになる
ことが確認されているので、前段により計算された膜厚
分布により、基板上全面に於ける膜厚分布が分かる。If the calculation at the preceding stage is repeated at predetermined time intervals for about six revolutions, the film thickness distribution at each predetermined time interval is obtained. The film thickness distribution in the radial direction is calculated by adding all the film thickness distributions at each of the predetermined time intervals. Since the rotation speed is set so as to be higher than the revolution speed and the revolution motion and the revolution motion do not interfere with each other, the radial film thickness distribution calculated in this manner is obtained by calculating all the different radii on the substrate. Since it is confirmed that the film thickness becomes the same in the directions, the film thickness distribution over the entire surface of the substrate can be determined from the film thickness distribution calculated in the preceding step.
【００２６】図２の装置構成の真空蒸着装置に、計算に
用いた基板と同じ形状の基板の基板面の半径上に所定の
間隔で複数の測定用平面基板を並べてセットし、蒸着試
料フッ化マグネシウムに電子線照射をして成膜を行なっ
た。成膜条件は、圧力１０ -4Ｐａ、基板加熱温度３００
℃ だった。このときの蒸発源形状は蒸発源モデルを作
ったときと同じ直径２０ｍｍの円形だった。In the vacuum deposition apparatus having the apparatus configuration shown in FIG.
The specified shape is set on the radius of the substrate surface of the substrate of the same shape as the used substrate.
A plurality of flat substrates for measurement are set side by side at intervals, and
Electron beam irradiation on magnesium fluoride to form a film
Was. The film formation conditions are pressure 10 -FourPa, substrate heating temperature 300
° C. The evaporation source shape at this time creates an evaporation source model.
It was the same circular shape with a diameter of 20 mm.
【００２７】成膜後、測定用平面基板の膜厚を分光光度
計により測定することにより膜厚分布を測定した。図４
には、この実測した膜厚分布◆と、本実施例により予測
された膜厚分布○と、従来技術により予測された膜厚分
布△とが比較して示されている。図４に於いて、横軸は
レンズ中心からの距離であり、縦軸はレンズ中心の膜厚
に対する半径方向の各点での膜厚の比を示している。従
来技術では蒸発源モデルが不適切なため、膜厚分布予測
結果は実測の膜厚分布と膜厚の比で最大０．０９と大き
く乖離している。しかし本発明による膜厚分布予測結果
は最大の乖離が０．０４以下と実測値と良い一致を示し
ていることがわかる。After the film formation, the film thickness distribution of the flat substrate for measurement was measured by a spectrophotometer. FIG.
FIG. 2 shows a comparison between the actually measured film thickness distribution ◆, the film thickness distribution 予 測 predicted according to the present embodiment, and the film thickness distribution △ predicted according to the prior art. In FIG. 4, the horizontal axis indicates the distance from the lens center, and the vertical axis indicates the ratio of the film thickness at each point in the radial direction to the film thickness at the lens center. In the prior art, since the evaporation source model is inappropriate, the result of the film thickness distribution prediction largely deviates from the actually measured film thickness distribution to the maximum film thickness ratio of 0.09. However, the film thickness distribution prediction result according to the present invention shows that the maximum deviation is 0.04 or less, which is in good agreement with the actually measured value.
【００２８】このようにして本発明は、蒸発源を極めて
適切且つ簡便にモデル化するので、真空蒸着法で実際に
成膜しなくても計算のみであらゆる形状の基板の膜厚分
布を高精度で予測できる。そのため、多様な形状のレン
ズ、プリズムなどの基板の膜厚分布を安価に且つ速く評
価することができる。そのため、半導体露光装置等の高
ＮＡ（ｎｕｍｅｒｉｃａｌ ａｐｅｒｔｕｒｅ）の投影
レンズ等に用いられる多様な形状のレンズに対しても、
高速、且つ安価に膜厚分布を評価できる。更に、この膜
厚分布から分光透過率等の分光特性を実際に薄膜形成を
行なわなくても評価できる。As described above, the present invention models the evaporation source extremely appropriately and simply, so that even if the film is not actually formed by the vacuum evaporation method, the film thickness distribution of the substrate of any shape can be calculated with high accuracy by only calculation. Can be predicted. Therefore, it is possible to evaluate the film thickness distribution of substrates having various shapes such as lenses and prisms inexpensively and quickly. Therefore, various shapes of lenses used for a projection lens having a high numerical aperture (NA) such as a semiconductor exposure apparatus are also required.
The film thickness distribution can be evaluated at high speed and at low cost. Further, spectral characteristics such as spectral transmittance can be evaluated from the film thickness distribution without actually forming a thin film.
【００２９】[0029]
【発明の効果】請求項１〜６の発明は、蒸発源を微小平
面蒸発源の集合によりモデル化しているので、従来の式
１を用いた膜厚分布の予測方法で問題であった、蒸発源
寸法が蒸発源基板間距離または蒸発源遮蔽板間距離に比
較して無視できないために生じていた予測膜厚分布と実
測膜厚分布との誤差を減らすことができる。また、物理
的根拠にも基づいているので、汎用性、応用性に富んで
いる。According to the first to sixth aspects of the present invention, since the evaporation source is modeled by a set of minute flat evaporation sources, there is a problem in the conventional method of predicting the film thickness distribution using the equation (1). The error between the predicted film thickness distribution and the actually measured film thickness distribution can be reduced because the source size cannot be ignored compared to the distance between the evaporation source substrates or the distance between the evaporation source shielding plates. In addition, since it is based on physical grounds, it is rich in versatility and applicability.
【００３０】また、請求項２〜６の発明は、各微小平面
蒸発源の膜厚分布を簡便な式２により算出するので、膜
厚分布を予測するための計算が簡便であり、従来の式１
を用いた膜厚分布予測方法で必要であったＬ、Ｍ、Ｎの
フィッティングパラメータを用いないため、フィッティ
ングパラメータを決定するための数十回に及ぶ実験を行
う必要がなく、簡便且つ正確に膜厚分布予測をすること
が可能となった。Further, in the inventions of claims 2 to 6, since the film thickness distribution of each minute planar evaporation source is calculated by the simple formula 2, the calculation for predicting the film thickness distribution is simple, and the conventional formula is used. 1
Since the L, M, and N fitting parameters required in the film thickness distribution prediction method using the method are not used, it is not necessary to perform dozens of experiments for determining the fitting parameters, and the film can be simply and accurately formed. The thickness distribution can be predicted.
【００３１】また、請求項３〜６の発明は、微小平面蒸
発源の数を比較的少ない５個でモデル化しているので、
簡便に膜厚分布を予測できる。また、請求項４〜６の発
明は、微小平面蒸発源を蒸発源の掘れ跡の形状を模して
配置されるので、どのような掘れ跡を有する蒸発源に対
しても直ちに正確に膜厚分布を予測できる。According to the third to sixth aspects of the present invention, since the number of minute flat evaporation sources is modeled by a relatively small number of five,
The film thickness distribution can be easily predicted. Further, according to the invention of claims 4 to 6, since the minute plane evaporation source is arranged to imitate the shape of the digging mark of the evaporation source, the thickness of the evaporation source having any digging mark can be accurately and immediately determined. The distribution can be predicted.
【００３２】また、請求項５〜６の発明は、適切な遮蔽
板を配置しているためにどのような形状の基板も膜厚分
布を均一化できるのみならず所定の膜厚分布を得ること
が出来る。また、請求項６の発明によれば、膜厚の予測
のみならず、薄膜が光学薄膜の場合に実際に薄膜形成し
なくても高精度に分光透過率等の光学特性の評価予測が
出来る。According to the fifth and sixth aspects of the present invention, since a suitable shielding plate is arranged, not only can the substrate of any shape have a uniform film thickness distribution but also a predetermined film thickness distribution can be obtained. Can be done. Further, according to the invention of claim 6, not only the prediction of the film thickness but also the evaluation and prediction of the optical characteristics such as the spectral transmittance can be performed with high accuracy without actually forming the thin film when the thin film is an optical thin film.
【図１】本実施形態の、任意蒸発源の複数の微小平面蒸
発源によるモデル化を示す。FIG. 1 shows modeling of an arbitrary evaporation source by a plurality of minute flat evaporation sources according to the present embodiment.
【図２】本実施形態の、膜厚分布予測に用いた真空蒸着
装置の模式図を示す。FIG. 2 is a schematic view of a vacuum evaporation apparatus used for estimating a film thickness distribution according to the present embodiment.
【図３】本実施形態の、膜厚分布予測に用いた蒸気遮蔽
板の上面図であり、開口形状を示す。FIG. 3 is a top view of a vapor shielding plate used for estimating a film thickness distribution according to the embodiment, showing an opening shape.
【図４】本実施例の、予測された膜厚分布と実測された
膜厚分布との比較を示す。FIG. 4 shows a comparison between the predicted film thickness distribution and the actually measured film thickness distribution in the present embodiment.
【図５】従来技術を説明するための成膜装置の模式図を
示す。FIG. 5 is a schematic view of a film forming apparatus for explaining a conventional technique.
【図６】基板ホルダの詳細図を示す。FIG. 6 shows a detailed view of the substrate holder.
【図７】従来の遮蔽板の上面図である。FIG. 7 is a top view of a conventional shielding plate.
【図８】式１、２で用いられている変数の意味を説明す
る図である。FIG. 8 is a diagram illustrating the meaning of variables used in Expressions 1 and 2.
１ 真空槽 ２ 蒸発源ユニット ３ 遮蔽板 ４ 基板（球面レンズ） ５ 基板ホルダー ６ 気化蒸気 ７ 遮蔽板の開口部 ８ 遮蔽板の遮蔽部 ９ 蒸発源 １０ 成膜装置 １１ 従来の遮蔽板の桟部 １２ 従来の遮蔽板の遮蔽部 １０６従来の遮蔽板 Ｃａ 公転軸 Ｃｂ 自転軸 DESCRIPTION OF SYMBOLS 1 Vacuum tank 2 Evaporation source unit 3 Shielding plate 4 Substrate (spherical lens) 5 Substrate holder 6 Vaporized vapor 7 Shielding plate opening 8 Shielding plate shielding portion 9 Evaporation source 10 Film forming apparatus 11 Conventional shielding plate beam 12 Shielding part of conventional shielding plate 106 Conventional shielding plate Ca revolution axis Cb rotation axis
Claims (6)
蒸気を基板上に堆積させる、真空蒸着法により基板上に
形成される薄膜の膜厚分布を予測する方法であって、前
記蒸発源を複数の微小平面蒸発源によりモデル化する段
階を具えることを特徴とする膜厚分布予測方法。1. A method for estimating a film thickness distribution of a thin film formed on a substrate by a vacuum evaporation method, wherein a substance of an evaporation source is vaporized in a vacuum and the vapor is deposited on the substrate. A method for predicting a film thickness distribution, comprising a step of modeling an evaporation source using a plurality of minute planar evaporation sources.
板上に形成される薄膜の膜厚（ｄ）の分布を、 ｄ∝Ｗcos θcos φ／ｒ2 ここで、Ｗ：各微小平面蒸発源の重み θ：基板に対する蒸気の入射角度 φ：蒸気の放射角度 ｒ：蒸発源と基板面との距離 なる式で算出する段階を具えることを特徴とする請求項
１記載の膜厚分布予測方法。2. The distribution of the thickness (d) of a thin film formed on the substrate by each of the micro-plane evaporation sources, where d∝Wcos θcos φ / r 2, where W: each of the micro-plane evaporation sources 2. The method according to claim 1, further comprising the step of calculating the following equation: θ: the incident angle of the vapor with respect to the substrate, φ: the radiation angle of the vapor, and r: the distance between the evaporation source and the substrate surface. .
ことを特徴とする請求項１、２何れか１項記載の膜厚分
布予測方法。3. The method for predicting film thickness distribution according to claim 1, wherein the number of said minute plane evaporation sources is five or more.
の掘れ跡を模して配置されることを特徴とする請求項１
〜３何れか１項記載の膜厚分布予測方法。4. The apparatus according to claim 1, wherein the plurality of minute planar evaporation sources are arranged so as to imitate a digging mark of the evaporation source.
4. The method for predicting film thickness distribution according to any one of claims 3 to 3.
な遮蔽板を配置することにより膜厚分布を所定の分布に
計算上補正する段階を具えることを特徴とする請求項１
〜４何れか１項記載の膜厚分布予測方法。5. The method according to claim 1, further comprising a step of arranging an appropriate shielding plate between said evaporation source and said substrate to correct the thickness distribution to a predetermined distribution.
5. The method for predicting film thickness distribution according to any one of claims 1 to 4.
測方法に記載された段階に加えて更に薄膜の光学特性の
分布を計算する段階を具えることを特徴とする光学特性
分布予測方法。6. A method according to claim 1, further comprising the step of calculating the distribution of the optical properties of the thin film in addition to the steps described in the method of predicting the film thickness distribution according to claim 1. Distribution prediction method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP32483199A JP2001140058A (en) | 1999-11-16 | 1999-11-16 | Method for estimating thin film thickness distribution and optical characteristic distribution |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP32483199A JP2001140058A (en) | 1999-11-16 | 1999-11-16 | Method for estimating thin film thickness distribution and optical characteristic distribution |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2001140058A true JP2001140058A (en) | 2001-05-22 |
Family
ID=18170179
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP32483199A Pending JP2001140058A (en) | 1999-11-16 | 1999-11-16 | Method for estimating thin film thickness distribution and optical characteristic distribution |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2001140058A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010138477A (en) * | 2008-12-15 | 2010-06-24 | Canon Inc | Vacuum deposition apparatus and method for forming film |
| CN102732844A (en) * | 2012-07-12 | 2012-10-17 | 中国科学院光电技术研究所 | Method for designing coating uniformity correction mask for spherical optical elements on planetary rotating jigs of vacuum coating machines |
| CN102787301A (en) * | 2012-07-23 | 2012-11-21 | 中国科学院光电技术研究所 | Design method for baffle plate used for controlling film thickness distribution on conical optical element in film plating planetary system |
-
1999
- 1999-11-16 JP JP32483199A patent/JP2001140058A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010138477A (en) * | 2008-12-15 | 2010-06-24 | Canon Inc | Vacuum deposition apparatus and method for forming film |
| CN102732844A (en) * | 2012-07-12 | 2012-10-17 | 中国科学院光电技术研究所 | Method for designing coating uniformity correction mask for spherical optical elements on planetary rotating jigs of vacuum coating machines |
| CN102732844B (en) * | 2012-07-12 | 2014-05-07 | 中国科学院光电技术研究所 | Method for designing coating uniformity correction mask for spherical optical elements on planetary rotating jigs of vacuum coating machines |
| CN102787301A (en) * | 2012-07-23 | 2012-11-21 | 中国科学院光电技术研究所 | Design method for baffle plate used for controlling film thickness distribution on conical optical element in film plating planetary system |
| CN102787301B (en) * | 2012-07-23 | 2014-03-26 | 中国科学院光电技术研究所 | Design method for baffle plate used for controlling film thickness distribution on conical optical element in film plating planetary system |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4474109B2 (en) | Sputtering equipment | |
| US6524449B1 (en) | Method and system for producing sputtered thin films with sub-angstrom thickness uniformity or custom thickness gradients | |
| US6858118B2 (en) | Apparatus for enhancing the lifetime of stencil masks | |
| CN103726019B (en) | Improve the method for design of the baffle plate of spherical optics element plated film homogeneity | |
| JP5695818B2 (en) | Cross-section processing method and cross-section observation sample manufacturing method | |
| WO2022110925A1 (en) | Laser-based direct optical control device for coating machine | |
| US20150025670A1 (en) | Substrate Processing Including Correction for Deposition Location | |
| JP2001140058A (en) | Method for estimating thin film thickness distribution and optical characteristic distribution | |
| US8790498B2 (en) | Method and device for ion beam processing of surfaces | |
| Sakiew et al. | Influence of ion beam parameters onto two-dimensional optical thin film thickness distributions deposited by ion beam sputtering | |
| KR100821810B1 (en) | Method of forming film on substrate | |
| US9257262B2 (en) | Lithography apparatus, lithography method, and method of manufacturing article | |
| TW593725B (en) | Coating device and method | |
| JP2005336535A (en) | Film deposition apparatus and film deposition method | |
| JP2005336535A5 (en) | ||
| CN112522671B (en) | Magnetron sputtering method, device, equipment and readable storage medium | |
| JPH11335820A (en) | Vapor deposition and vapor deposition device | |
| JP6219594B2 (en) | Thin film forming apparatus and thin film forming method | |
| US20240167145A1 (en) | Method for depositing a layer optical element, and optical assembly for the duv wavelength range | |
| CN117821906B (en) | Optical lens coating method | |
| US6254934B1 (en) | Method for controlled deposition of mirror layers | |
| CN117488248B (en) | Correction plate design method, correction plate, coating device and coating method | |
| Bosch | Geometrical limiting performances of a thermal evaporation PVD unit for lens coating | |
| US20130220794A1 (en) | Apparatus and method for multi-source deposition | |
| JP3395224B2 (en) | Thin film forming method and apparatus, and optical component |