| 摘要 |
1,262,013. Semi-conductor devices. INTERNATIONAL BUSINESS MACHINES CORP. 15 April, 1969 [17 April, 1968], No. 19287/69. Heading H1K. The major portion of a planar diffused junction in a semi-conductor capacitor comprises a series of interconnected arcs when viewed in a plane perpendicular to the planar surface of the device. In the Si PN-junction capacitor illustrated the apertures formed in a SiO 2 coating to define the extent of B-diffusion into an N-type substrate 15 comprise two mutually perpendicular intersecting sets of parallel strips spaced apart to such a degree that the diffusion fronts just overlap in the manner shown. In a modification the diffusion fronts do not overlap, but a shallower, higher concentration P-type zone (31), Fig. 6 (not shown), is formed by a subsequent B-diffusion process to interconnect all the hemispherical B-doped zones. One of the two sets of parallel strips may be omitted. Al electrodes are provided as shown at 22 on the diffused P-type region and also on a P-diffused n+contact area elsewhere in the substrate 15. Details of the preferred B and P diffusion processes are given, alternative processes involving a two-stage drive-in technique or a single-stage process resulting in a complementary error function distribution.
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