| 摘要 |
PURPOSE:To improve high-frequency characteristics of a semiconductor device by covering a mesa stepped portion with a photoresist and by forming the finger and lead portions of a gate by separate exposure in a different amount of exposure and by simultaneous development. CONSTITUTION:After a mesa stepped portion 1 is formed, an insulating film of a spacer is made to grow, and a photoresist 5 is applied on the upper surface thereof. Subsequently, a photomask having openings for a gate finger portion 2 and a connecting portion 3 thereof with a gate lead portion is superposed thereon and first exposure is conducted. Then, a photomask having an opening for the gate lead portion 4 is superposed on a pattern for which exposure is finished, and second exposure is conducted. The amount of exposure at this time is made larger than that of the first exposure so that the photoresist 5 is not left on the slope of the mesa stepped portion 1 after development. Accordingly the gate finger portion 2 and the gate lead portion 4 are formed on the mesa stepped portion 1 by separate exposure processes, and the minute finger portion 2 is formed easily. Thereby a high-frequency characteristic is improved. |
