Pattern formation

Abstract

Abstract PURPOSE:To form a gate T-type in cross-section with shorter length of the part of contact with the active region of the semiconductor device than conventional and with a larger dimension of its upper part, by a method wherein apertures are formed each in the upper and lower resist films to electrode dimension, and an electrode metal material is evaporated; then, the metal material except in electrodes is removed. CONSTITUTION:A non-doped GaAs buffer layer 2 and an N-GaAs active layer 3 are successively epitaxially grown on a semi-insulation GaAs substrate 1; further, the lower resist film 4 of resist CMR and the upper resist film 5 of resist EBR-9 are successively formed by coating. Next, these resist films are irradiated with electron beams in amounts of irradiation shown by the line diagram of Fig. (b). The transverse axis represents positions on the upper resist film 5, and the longitudinal axis represents amounts of irradiation and intensities: an amount of irradiation Da indicated by a numeral 7 and an amount of irradiation Do indicated by a numeral 6 express the amount of irradiation of auxialiary exposure only to the upper resist film 5 and the amount of irradiation of exposure to the lower resist film, respectively. Then, as shown by Fig. (d), a gate recess 10 is formed by wet etching with the mask of the resist film with an aperture 9, and a gate metal material 11 is evaporated.

Inventors

• 👤 Yoshimi Yamashita
• 👤 良美 山下
• 👤 Kinshiro Kosemura
• 👤 小瀬村　欣司郎
• 👤 Hidetoshi Ishiwari
• 👤 石割　秀敏
• 👤 Sumio Yamamoto
• 👤 純生 山本

Bibliographic Details