| 摘要 |
<p>1,242,681. Masked diffusion. GENERAL ELECTRIC CO. 27 Sept., 1968 [13 Oct., 1967], No. 46116/68. Heading H1K. A diffusion process uses as a mask an apertured metal film formed on a passivating film on the surface of a semi-conductor body. Diffusion may take place through the unbroken passivating film or this may also be apertured, in correspondence with the metal film. The metal film may be used as an etching mask for this passivating film. Typical semi-conductors are silicon, germanium, and A<SP>III</SP>B<SP>V</SP> compounds such as gallium arsenide. Dopants used are boron and phosphorus. Diffusion may be from the gaseous phase or from a doped silicon layer on the semi-conductor or on its passivating layer. The masking metal, which should not react with the passivation, may be molybdenum or tungsten. Passivants used are silicon oxide, silicon nitride, and silicon oxynitride. The specific embodiment is a lateral transistor with concentric aluminium disc and annulus collector and emitter electrodes-the metal mask is left in place under a phosphorus-doped silicon oxide film used as the diffusion source for forming the emitter and collector layers.</p> |
