MULTILAYER OPTICAL FILM THICKNESS CONTROL METHOD, MULTILAYER OPTICAL FILM MANUFACTURING METHOD, AND MULTILAYER OPTICAL FILM SPUTTERING APPARATUS

To realize a film thickness control method, a multilayer optical film manufacturing method, and a sputtering apparatus with which the film thickness of each optical film may be adjusted upon forming a multilayer optical film.SOLUTION: A regression equation representing relationship between the thickness of optical film and optical characteristic value of a multilayer optical film is prepared, which is obtained by regression analysis of a theoretical optical characteristic value group of the multilayer optical film to which a combination of film thicknesses of each optical film is assigned. A model equation representing relationship between the level of change in manufacturing parameters of a manufacturing apparatus used to form an optical film and the level of change in the film thickness of the optical film and change in the thickness of the optical film is prepared. The optical characteristic value of the multilayer optical film actually formed is measured, and the actual measurement value is obtained. By applying the measured value to the regression equation, the estimated film thickness deviation from a standard film thickness of each optical film is calculated. By applying the estimated film thickness deviation level to the model equation, an adjustment level of the manufacturing parameter necessary to bring the film thickness deviation level of each optical film close to 0 is calculated. The manufacturing parameters are changed based on the adjustment level.SELECTED DRAWING: Figure 3 【課題】多層光学膜を成膜する際、各々の光学膜に対して膜厚調整を行なうことが可能な膜厚制御方法、多層光学膜の製造方法、スパッタ装置を実現する。【解決手段】光学膜各々の膜厚の組み合わせが割り振られた多層光学膜の理論上の光学特性値群を回帰分析して得られた、光学膜の膜厚と多層光学膜の光学特性値との関係を表わす回帰式を準備。成膜装置について光学膜の成膜に用いる製造パラメータの変更量と光学膜の膜厚の変化量の関係を表わすモデル式を準備。実際に成膜された多層光学膜の光学特性値を測定しその実測値を求める。実測値を回帰式に当てはめて、光学膜各々の基準膜厚からの推定膜厚偏差量を算出。推定膜厚偏差量をモデル式に当てはめて、光学膜各々の膜厚偏差量をそれぞれ０に近付けるために必要な製造パラメータの調整量を算出。調整量に基づいて製造パラメータを変更。【選択図】図３