Document Type
Thesis
Date of Award
6-30-1990
Degree Name
Master of Science in Electrical Engineering - (M.S.)
Department
Electrical and Computer Engineering
First Advisor
Durgamadhab Misra
Second Advisor
Kenneth Sohn
Third Advisor
N. M. Ravindra
Abstract
This thesis presents the damage effects to the Si ? SiO2 structures due to Reactive Ion Etching (RIE). The research was carried out on Si ? SiO2 MOS capacitors which were fabricated using RIE and wet etch (Hydrofluoric acid etch (HFE)) Process. The experiment was carried out using CV technique and Ellipsometry. Various electrical parameters were measured from CV *curves of these MOS capacitors. It was observed that the CV curve obtained for the RIE etched sample showed considerable deviation from that of the control sample. This indicates the presence of excess of interface trap charge density which have resulted due to the contamination of the silicon-oxide interface during etching. We have measured three different samples and the flatband voltage shift with respect to the control sample are -0.6290, -0.4265, and -0.0460 respectively. The shifting in the flatband voltage indicates that impurities due to radiation damage or metallic contamination, arising from the sputtering of the chamber wall during etching, are present in the interface. The RIE etched samples have also shown the presence of fast surface states which are recombination-generation centers resulting from the lattice disorder occttring near the interface during etching. High temperature annealing and hydrogen passivation can reduce the effects of these damages. The refractive index for both HF and RIE etched samples showed a difference of 0.014, 0.015, -0.001, and 0.009 respectively. This shows that any nature of disorder was not detected by the above measurement.
Recommended Citation
Bunyan, Moshe D., "Damage effects to Si-SiO2 structures due to reactive ion etching" (1990). Theses. 2508.
https://digitalcommons.njit.edu/theses/2508
