Exposure by electron beam

Abstract

Abstract PURPOSE:To prevent the lowering of pattern precision by a method wherein an irregularity on a sample is scanned plural times while the intensity of the objective current of an electron optical system for exposure is changed, the height of the sample is measured on the basis of the contribution of the contrasts of reflected electronic signal waveforms and the measured height is added to the drawing conditions. CONSTITUTION:In case a smaple 1 having a protrusion 2 is scanned with an electron beam 3 and a pattern is drawn, a reflected electron detector is provided, the focal length of the electron beam 3 is made to change little by little according to changing the intensity of the objective current of an electron optical system for exposure and the sample 1 is scanned in such a way that the electron beam 3 transverses the protrusion 2. The distribution curve of contrast is obtained from the objective current and the contrast value at the sacnning time, thereby finding the objective current at the time when the contrast becomes maximum. By applying the relation between the objective current at the time of the previously found maximum contrast and the length of the sample 1, the height of the sample 1 is decided and the result is made to feedback to the drawing conditions such as the adjustment of deflecting voltage, etc.

Inventors

• 👤 Mamoru Nakasuji
• 👤 護 中筋
• 👤 Kazuo Tsuji
• 👤 和夫 辻
• 👤 Izumi Kasahara
• 👤 笠原　泉
• 👤 Yoshio Suzuki
• 👤 鈴木　美雄

Bibliographic Details