| 摘要 |
1,053,104. Semi-conductor devices. SIEMENS & HALSKE A.G. Aug. 19, 1964 [Aug. 20, 1963], No. 33812/64. Heading H1K. A partially flat PN junction is produced by increasing the resistivity of an annular zone by diffusion and alloying a flat impurity body to produce an alloyed zone of opposite conductivity type, the boundary of the alloyed zone falling within the annular diffused zone. The high resistance diffused region prevents voltage breakdown which otherwise tends to occur in this region due to excessive curvature of the junction. Fig. 4 shows an embodiment in which an N-type annular high resistivity region 7 has been produced in a P-type silicon body 1 by diffusion of phosphorus from P 2 O 5 through window 6 etched in a silicon oxide coating 5. N-type region 3 was then produced by alloying a flat disc 2 of gold-antimony alloy into the silicon so that the peripheral region of the alloyed PN junction extended into region 7. In a further embodiment, B 2 O 3 was utilized to diffuse boron into an N-type silicon body to form the annular high resistivity zone and a disc of aluminium or gold-boron alloy was used to form the alloyed zone in the silicon body. Silicon carbide could be used in place of silicon. In another embodiment an additional diffused annular zone of the same conductivity type as the body was provided around the high resistivity diffused annular zone of opposite type, this second zone acting to prevent the formation of interfering channels. |
