PHASE-CONTROLLED MODEL-BASED OVERLAY MEASUREMENT SYSTEM AND METHOD

• Main Author: JEONG HWAN J
• Format: Patent
• Language: English; Japanese
• Published: 26.02.2015
• Subjects: BASIC ELECTRIC ELEMENTS; CALCULATING; COMPUTING; COUNTING; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; MEASURING; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS; MEASURING LENGTH, THICKNESS OR SIMILAR LINEARDIMENSIONS; PHYSICS; SEMICONDUCTOR DEVICES; TESTING

PROBLEM TO BE SOLVED: To provide an overlay error measurement method for measuring overlay errors precisely, even when overlay targets are substantially smaller than those currently in use and are surrounded by other patterns.SOLUTION: An overlay measurement system 100 and method are disclosed that control a relative phase between a scattered component 116 and a specular component 114 of light to amplify weak optical signals before detection. The system and method utilize model-based regression image processing to determine overlay errors accurately even in the presence of inter-pattern interference. 【課題】オーバーレイ標的が現在使用されている標的よりも実質的に小さく、かつ、他のパターンによって囲まれている場合においても、オーバーレイ誤差を正確に測定するオーバーレイ誤差の測定方法を提供する。【解決手段】光の散乱成分１１６と反射成分１１４との相対位相を制御し、検出前の弱い光信号を増幅させる、オーバーレイ測定システム１００及び方法である。システム及び方法は、モデルに基づく回帰画像処理を利用して、パターン間干渉の存在下においてもオーバーレイ誤差を正確に決定する。【選択図】図１Ａ