The Tegal 700 plasma etcher was used to etch trenches into four micron deep p-type diffused resistors to evaluate the quality of the electrical isolation. Etch times of nine and twelve minutes were used to etch trenches approximately 7.B and 11.5 microns respectively. Current flow was detected in all resistors, despite the fact that the trench should have resulted in open circuits. Therefore, at this time, results are inconclusive.
Curcio, John P.
"Trench Isolation Studies,"
Journal of the Microelectronic Engineering Conference: Vol. 3
, Article 11.
Available at: http://scholarworks.rit.edu/ritamec/vol3/iss1/11