| 摘要 |
<p>PURPOSE:To obtain semiconductor devices having no variation of the characteristics and no fluctuation of the characteristics by a method wherein, when FET's or diodes are formed on the face (100) of a semiconductor crystal, the directions of their gates and anodes are in parallel with each other and along the face (101) or face (001) which are little influenced by the internal stress of laminated films. CONSTITUTION:If two FET's are formed on a semiconductor substrate along directions (A) and (B) as shown in the figure, their threshold voltages are significantly different from each other when the gate lengths are short. On the other hand, if they are formed along directions (C) and (D) as shown in the figure, no difference exists between the voltages. The cause of this phenomenon is through to be such that a stress is applied to the end of the gate by the internal stress of laminated films and, as a result, charges are induced in the crystal under the gate by a piezoelectric effect and the carrier concentration of an active layer is changed. In order to avoid this phenomenon, therefore, when the FET's are formed on a crystal having a face (100), the directions of laying the gates are along the face (010) or face (001) as shown by (C) and (D) in the figure to provide the threshold voltages equal to each other. When this constitution, breakage of the substrate which occurs when the crystal is cut can be also avoided.</p> |
