| 摘要 |
PURPOSE:To obtain a high gm characteristic and to obtain a composite device with a bipolar transistor (Bip-Tr) on the same substrate, by holding the channel of a junction type J-FET by high-concentration lower and upper gate regions. CONSTITUTION:An N layer 12 for Bip-Tr is embedded in a P-type Si substrate 11. An N epitaxial layer 13 on the substrate 11 is isolated by a P layer 14, and an N<+> lower gate layer 15 for a J-FET is formed. An N epitaxial layer 16 is overlapped, and an SiO2 mask 17 is provided. The layer 16 is isolated with a P layer 18 by diffusion. A P-base layer 18a, a P-type source layer 18b and a drain layer 18c are formed. An N-emitter layer 19a and an N-connector- layer connecting layer 19b are similarly formed. Patterning for forming a channel is performed. Ions are implanted through a thin oxide film 20, and a P channel 21 and an N-type upper gate layer 22 are formed. In this constitution, the J-FET having high gm can be formed on the same substrate together with the Bip-Tr. |
