| 摘要 |
<p>855,382. Semiconductor devices. SARKES TARZIAN Inc. Feb. 25, 1957 [March 9, 1956], No. 1229/60. Divided out of 855,381. Drawings to Specification. Class 37. A method of producing a PN junction comprises applying to a surface of a mono crystalline body of one conductivity type a dot comprising an activator or the opposite conductivity type, placing a second dot consisting of pure tin on the first dot, heating to a temperature between the melting points of the semiconductor and first dot, and cooling to form the junction on recrystallisation. In one embodiment a first dot of gallium and aluminium is applied to an N type silicon wafer followed by a tin dot. After application of a thin sheet of tin to the opposite face of the wafer the assembly is fired at 950 ‹C. and subsequently cooled. During heating the tin mixes with the aluminium gallium so that the metal solidifying over the initial regrown P type region contains a high proportion of tin the ductility of which reduces the strains occurring at the junction during cooling. The resulting device may be soldered between two metal plates forming electrodes. In an alternative method the assembly is mounted during the firing on a metal electrode so that on cooling it is attached thereto via the tin sheet. In this case the other electrode is welded to the composite dot subsequently by passing a current into it via the electrode.</p> |
