公开(公告)号：JPH07201889A

公开(公告)日：1995-08-04

申请号：JP30654394

申请日：1994-12-09

Applicant: KOREA ELECTRONICS TELECOMM

Inventor： YOU TENKIYOKU ,  GO OUKI ,  IN KIYOUSHIYOU ,  RI SHINKI ,  BOKU TETSUJIYUN ,  BOKU KIYOUMO

IPC: H01L29/43 ,  H01L21/30 ,  H01L21/338 ,  H01L29/423 ,  H01L29/49 ,  H01L29/812

Abstract: PURPOSE: To simplify the forming process of a fine pattern and a T-shape gate by doubly exposing a photoresist film through the use of an optical stepper, making it the photoresist film of a lower layer, forming the photoresist film of an upper layer on it and applying a metallic film on it. CONSTITUTION: A photoresist film 20 is applied on the semi-insulating GaAs substrate 10. A photomask 30 having an opaque region 31 is arranged on it and the region of a gate is exposed by the exposure of ultraviolet rays. When the region is exposed again in a state in which the photomask is moved for a prescribed distance, the regions which are not exposed are again classified as a region 22 which is not exposed and regions 23 which have been exposed once, and the region except for the regions is the region that has been exposed twice. Thus, a pattern which is finer than the resolution of the applied stepper can be formed in the formation of the fire form, and the form of the T-shape gate can efficiently be formed.

公开(公告)号：JPH08186128A

公开(公告)日：1996-07-16

申请号：JP31538694

申请日：1994-12-19

Applicant: KOREA ELECTRONICS TELECOMM

Inventor： RI SHINKI ,  SAI SOUSHIYU ,  IN KIYOUSHIYOU ,  BOKU CHIYURUJIYUN ,  YU KEISHIYUN ,  BOKU KIYOUMO

IPC: H01L21/027 ,  H01L21/336 ,  H01L21/338 ,  H01L29/778 ,  H01L29/78 ,  H01L29/786 ,  H01L29/812

Abstract: PURPOSE: To reduce the resistance and parasitic capacitance of a fine gate by irradiating the upper and lower parts of the gate with an electron beam having different intensity of energy. CONSTITUTION: A two-dimensional electron gas layer 2, an AlGaAs layer 3 and a doped Schottky layer, i.e., a cap layer 4, are formed sequentially on a substrate 1 followed by formation of ohmic layers 5a, 5b. A resist 6 is then applied to the cap layer 4 and heat treated. Subsequently, a second resist 7 is applied onto the first resist 6 and an exposure step is executed using an electron beam having uneven energy. In order to form a T type gate, first and third electron beams 8a, 8c have energy of such intensity as exposing only the second resist 7 while a second electron beam 8b has energy of such intensity the first and second resists 6, 7 can be exposed entirely.