| 摘要 |
958,521. Transistors. PHILIPS ELECTRICAL INDUSTRIES Ltd. Jan. 27, 1961 [Jan. 30, 1960], No. 3258/61. Heading H1K. In a transistor, at least a portion of the base zone is provided by diffusing during the alloying of the emitter, an impurity to convert a region of the body of one conductivity type to the opposite type, the contact material used for the alloy-diffusing process being free of the lifetime reducing impurity which initially exists throughout the body. The concentration of the lifetime reducing material is thus reduced in that portion of the base zone lying between the emitter and the collector. Fig. 3 shows a P-type gold-doped germanium wafer 3 to which a first pellet 5 containing lead with 5% antimony and 1% aluminium and a second pellet 6 of lead with 5% aluminium have been fused. Heating for 6 minutes at 750‹ C. provides an N-type base layer 4 due to diffusion of the antimony and recrystallized layers 7 of N-type material and 8 of P-type containing aluminium. During the process gold from the body diffuses into the contacts leaving the base zone 4 with reduced concentration of gold. Other lifetime reducing impurities such as nickel, iron or copper may be used, and silicon may be used instead of germanium. Indium, gallium and arsenic may be used as impurities for the alloying and diffusing process. A masking lacquer layer may be provided between base and emitter contacts 5 and 6 and the remaining semi-conductor surface then etched away to provide a transistor as shown in Fig. 4. |
