| 摘要 |
1,224,802. Semi-conductor devices. SONY CORP. 5 April, 1968 [7 April, 1967 (2)]. No. 16425/68. Heading HlK. A method of manufacture of a silicon transistor having a base which has both a thin region 16 to give good current amplification and thick regions 14 to allow easier connection of electrical leads comprises the selective deposition of a P-type impurity into an N-type silicon substrate 10, Fig. 1D, and heating to diffuse this impurity into the substrate to form a plurality of P-type regions 14, then forming a thin P-type layer 16 overall by vapour deposition, covering this with an N-type collector layer 18 and a N + -type layer 20, then etching through the layers 16, 18 and 20 deep into the P-type regions 14 to produce a series of mesa structures which are provided with electrodes and separated to give the final device of Fig. 1G. In a further embodiment, Fig. 2 (not shown), the step of etching into the P-type regions 14 is replaced by the selective diffusion of P-type impurity through the layers 16, 18 and 20 into the P-type regions 14 to produce thick regions (44) of the base to which leads may be attached. In a further embodiment, Fig. 4 (not shown), after the formation of layers 16, 18 and 20 the underside of the wafer is removed to expose the P-type regions 14. Electrodes (26) to these regions and (28) to the N-type regions between them are then deposited together with an electrode (24) to the collector layer 18. |
