SEMICONDUCTOR DEVICE HAVING COMPLEMENTARY TRANSISTOR STRUCTURES AND METHOD OF MANUFACTURING SAME

摘要

1505103 Semiconductor devices PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd 21 May 1975 [18 June 1974] 21807/75 Heading H1K At least two complementary bipolar transistors T1, T2 are formed in a body comprising two epitaxial layers 2, 3 of opposite type with the base zone of transistor T1 formed by at least a part of the lower layer 2, the base zone of transistor T2 formed by at least a part of the upper layer 3 and the collector of transistor T2 formed by at least a part of the lower layer 2. The transistor T1 has a zone 6 of the same type as layer 3 surrounding the epitaxial portions and constituting the collector or emitter region, and has a further zone 7 of the same type as the lower layer 2, but more highly doped, surrounding an emitter or collector region 8 and constituting a connection region to the base 2. In one embodiment, as shown, the epitaxial layers 2, 3 containing the complementary transistor structures are formed as insulated islands in a polysilicon substrate 1 with an outer barrier 5 of SiO 2 . The transistor regions are formed by diffusion or ion implantation and the islands are shaped in standard masking and etching steps while the epitaxial layers are held on a temporary handling substrate (Figs. 2, 3, not shown). The region 7 may also include a lateral portion within the layer 2 (Fig. 6, not shown). In other embodiments, the transistors are isolated by reverse bias PN junctions and there may be three epitaxial layers in which a thyristor structure is formed (Figs. 8, 15, not shown).