Passivation Coatings on Silicon Devices

Abstract

Passivation coatings are widely used to improve the performance and reliability of silicon devices of various types, ranging from discrete mesa‐type diodes and transistors to complex planar silicon integrated circuits, and including both hermetic and plastic‐encapsulated devices. This paper reviews the materials and techniques used to apply passivation coatings to completed silicon devices. Principal production techniques used in passivation of silicon devices include thermal oxidation, high‐temperature diffusion, high‐temperature chemical vapor deposition of or , low‐temperature chemical vapor deposition of glasslike or phosphosilicate layers (deposited at approximately 400°C), rf sputtering of , mechanical deposition of glass frit layers which are subsequently fused, and application of organic polymer films.The effects of passivation layers on silicon device reliability are discussed, and the interrelationships among the silicon device, the passivation layer or layers used and the final encapsulation are indicated. Pertinent references on passivation and on related topics are cited in the text.