GATE FORMATION OF FIELD-EFFECT TRANSISTOR

    公开(公告)号:JPH08186128A

    公开(公告)日:1996-07-16

    申请号:JP31538694

    申请日:1994-12-19

    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.

    METHOD FOR MANUFACTURING T-SHAPED GATE BY DOUBLE EXPOSURE

    公开(公告)号:JPH07201889A

    公开(公告)日:1995-08-04

    申请号:JP30654394

    申请日:1994-12-09

    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.

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