| 摘要 |
1,231,566. Semiconductor devices. MITSUBISHI DENKI K.K. 11 June, 1969 [13 June, 1968], No. 29521/69. Heading H1K. An integrated circuit is produced on a body of semi-conductor material of one conductivity type by providing a highly doped region of the opposite conductivity type on part of one face, growing a layer of material of the one conductivity type on that face, growing a layer of material of the opposite conductivity type on the first grown layer, and causing impurities to diffuse from the highly doped region into the portion of the first grown layer in direct contact with it to convert this portion to the opposite conductivity type during a heat treatment. As shown, Fig. 2c, an N + type region 12 is formed in the surface of a P-type Si substrate 10 by selective diffusion and is covered with a P- type epitaxial layer 20 and an N-type epitaxial layer 14. Selective diffusion is utilized to form a P-type isolation region 16 extending from the surface to the P-type layer 20 and during this diffusion impurities diffuse from the N + type region into the overlying part of the P-type layer 20 to form N-type region 22. A P-type region 18 is then diffused-in to form a diode and electrodes are applied to region 18 and to the exposed part of region 14 encircled by the isolation region 16. The P- and N-type epitaxial layers may be produced by continuous growth, the impurity being changed when desired. The diode region 18 and the isolation region 16 may be simultaneously produced by a single selective diffusion step. Other types of semi-conductor devices may be formed in isolated regions e.g. transistors. The resistivity of the N-type epitaxial layer may be measured using a fourpoint probe before the formation of region 22. |
