| 摘要 |
PROBLEM TO BE SOLVED: To provide a manufacturing method of an HBT wherein the operational speed of the HBT is made high without overetching reaching its base layer. SOLUTION: In the case that the collector layer and the base layer of the HBT are formed of materials capable of being etched by the same etchant, respective, the manufacturing method of the HBT includes a process (1) for laminating a sub-collector layer, a collector layer, a base layer, and an emitter layer on a substrate, a process (2) for exposing the collector layer after forming an emitter electrode and a base electrode, a process (3) for etching and removing about a half in the thickness of the collector layer except under the base layer to make the thickness of the portion nearly the half of the original thickness of the collector layer and for stopping the etching halfway through the process, a process (4) for applying a mask to the predetermined region above the collector layer which includes the emitter and base electrodes to cover the predetermined region, and a process (5) for side-etching the collector layer including the interposed portion between the base electrode and the sub-collector layer to form a desired air gap. COPYRIGHT: (C)2004,JPO
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