MANUFACTURE OF SEMICONDUCTOR DEVICE

• Main Author: SUMIYA KOICHI
• Format: Patent
• Language: English
• Published: 29.05.1992
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

PURPOSE:To enable a T-type gate shape to be formed easily and with improved reproducibility or prevent let-go of a gate metal or contact failure, etc., since the T-type gate electrode is a continuous one-piece object by forming a recessed part of the gate-forming part to be in taper shape. CONSTITUTION:After forming a resist pattern which is 0.25mum wide on a semi- insulation GaAs substrate 1 by electronic beam exposure and the depositing an SiN film by the ECR-CVD method, a dummy gate 2 is formed by lift-off. Then, an SiO2 film 3 is deposited on an entire surface and an upper surface of the dummy gate 2 is exposed by the etch-back method. Then, an SiN film 3a of the dummy gate 2 is eliminated by etching using the reactive ion etching method. At this time, when sputter etch effect is reinforced, the edge of an SiO2 film 3b around the dummy gate 2 becomes a taper shape. Then, an Al film 4 which becomes a gate metal is formed. In this state, a T-type gate shape is formed but it is possible to eliminate the SiO2 film 3b by etching when the SiO2 film 3b at the lower part of the T-type gate becomes a parasitic capacity and the amount of deterioration of FET characteristic is large.