CONTROLLED DEFECT GENERATION IN POROUS SILICON
EMSL Project ID
8220
Abstract
Nanoporous silicon surface has been subject to considerable study because of its photoemmsion properties and possible opto-chemical, gas and bio sensing applications. The ability to get controlled defects form on this surface may lead to tuning or adjustment of specific properties. Hydrogen bubble formation from silicon surface during chemical etching is a routinely observed process. In electrochemical etching experiments, etch-current density in silicon is directly related to the etch-rate which is proportional to the rate of hydrogen (H2) evolution. We have already observed bubble shaped defects containing nanopores at the hydrogen (H2)-buffer oxide etch (BOE) solution bubble interface on a heavily n-doped <100> single crystal silicon. There is some evidence to suggest that pinning in these hydrogen bubbles is possible at some random sites which are believed to be surface defect sites. The aim of this project will be to create well ordered pinning centers on silicon using photolithography and study the effect of bubble pinning around these sites by changing etch parameters. We believe that slower hydrogen evolution from silicon surface would create sufficient bubble residence time for circular bubble shaped defects. The role of current carrying Si-OH species and bubble stability on silicon surface will be studied in details.
Project Details
Project type
Exploratory Research
Start Date
2004-05-10
End Date
2006-04-13
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members