Depth-Resolved Imaging of Radiation-Induced Doping Changes in Silicon. (27th October 2015)

• Record Type: Journal Article
• Authors: Dang, Z. Y.; Breese, M. B. H.
• Is Part Of: ECS journal of solid state science and technology. Volume 4:Number 12(2015)
• Page Start: P462
• Page End: P467
• Publication Date: 2015-10-27
• Subjects: annealing -- doping microscopy -- ion irradiation -- silicon electrochemistry; Solid state chemistry -- Periodicals; Electronics -- Materials -- Periodicals; Electrochemistry -- Periodicals; 541.0421
• DOI: 10.1149/2.0261512jss
• Languages: English
• ISSNs: 2162-8777

Abstract

Abstract : We present a method for imaging variations in the doping depth profile in n- and p-type silicon induced by high energy ion irradiation. This doping microscopy method is based on electrochemical anodization of irradiated wafers, producing porous silicon with a local porosity depending on doping changes. In moderately-doped n-type silicon a higher porosity corresponds to where irradiation creates excess donors and a lower porosity corresponds to where acceptors are created. Higher porosity regions may be selectively removed and so observed in cross-section images. We compare the effects of proton and helium ion irradiation on the localized doping in n-type Czochralski silicon, with and without annealing at 300°C. Even at such a low annealing temperature, a pronounced n + doping is observed for helium irradiation, highly confined to just the irradiated volume. In comparison, proton irradiation results in weaker n + doping which extends beyond the irradiated region, attributed to hydrogen diffusion.