| 摘要 |
1,046,721. Semi-conductor devices. STANDARD TELEPHONES & CABLES Ltd. Feb. 13, 1964 [Feb. 15, 1963], No.6258/63. Heading H1K. A P-N junction semiconductor device includes a body 1 of semiconductor material of one conductivity type having a layer 2 of semiconductor material of opposite conductivity type immersed in the body so that part of the body material surrounds and inwardly overlaps the layer material to expose a surface of the layer, the thickness of the overlapping portions of the body material being less than the spread of a space charge region set up by application to the junction of a reverse bias voltage such as to cause avalanche breakdown within the body material. The body material has a high resistivity compared with the layer material. The device may be made by depositing epitaxially a P-type silicon layer on a slice of N-type silicon, removing part of the layer by etching or air abrasion to leave an area corresponding in size to the required layer 2, and depositing a layer of N-type silicon on the slice to cover the P-type layer. Phosphorus pentoxide is then deposited on the lower face of the slice and heat is applied to diffuse the phosphorus pentoxide into the silicon to form a low-resistivity contact area 4 and to diffuse the P-type material into the surrounding N-type material to form the junction 3. The overlying N-type material is then excavated by etching or air abrasion to expose the layer 2. |
