| 摘要 |
PURPOSE:To reproduce a gate shape similar to a gate pattern by a method wherein an originally formed gate pattern is converted into reverse shape as a gate opening on a coating film and then heat-treated to recover crystallinity and the gate opening is refilled with gate metal. CONSTITUTION:A plasma silicon nitride film 23, an N type operating layer 5, a silicon oxide film 21 and another plasma silicon film 22 are formed on a high resistance GaAs substrate 4 and then the film 21 is side-etched to form a gate pattern 21 and a high concentration conductive layer 6 is formed utilizing the film 22 as a mask. After forming a plasma nitride film 24 and a photoresist film 26 on overall surface, the pattern 21 is exposed by etching process and removed to make an opening. Later the crystallinity of the layers 5, 6 is recovered by heattreatment and the film 24 under the opening is removed to expose the layer 5. A gate electrode 1 is formed in this opening. Through these procedures, a gate shape similar to a gate pattern may be reproduced. |
