Process for sandblasting silicon slabs as part of semiconductor transistor manufacture

Abstract

Aim. The paper aims to develop a process for treating the back side of silicon slabs and giving them a surface texture that enables good adhesion with printed metal with an even thickness and no mechanical stress, cracks or chipping. That is achieved by sandblasting slabs before contact material application. Silicon carbide (SiC) with particle size not exceeding 6 um is used as the abrasive material. Methods. The proposed method of sandblasting improves chip bonding by eliminating surface stress, formation of microcracks and crystal grain within the chip. The research was conducted using a sandblaster and electronic microscope. Results. It was shown that, after sandblasting, metal coating in the process of transistor collector area contact delineation improves the adhesion of the substrate semiconductor. Additionally, no mechanical stress was observes as compared to grinding, polishing and chemical treatment that are normally done before transistor contact encapsulation. Conclusions. The process of thin metal film evaporation as part of semiconductor-based device manufacture affects their dependability. The treatment and preparation of the back side of the silicon slab with finished transistor configurations is one of the key operations as part of transistor manufacturing process that affects the adhesive properties of the surface before evaporation, output characteristics of the semiconductor-based devices, yield and cost.