Date of Award
1988
Degree Type
Dissertation
Degree Name
Doctor of Philosophy
Abstract
In secondary ion mass spectrometry (SIMS) the detected ion count rate must be corrected for differences in matrix when depth profiling semiconductor samples with layered structures of different composition. Few published studies of the matrix effect exist and those that have studied the matrices give widely differing factors. The situation is further complicated by secondary ion molecular interferences which can completely mask the ion signal of interest. These problems are examined in this thesis.;The depth distribution of ion implanted samples of {dollar}\sp{lcub}28{rcub}{dollar}Si and {dollar}\sp{lcub}52{rcub}{dollar}Cr in Al{dollar}\sb{lcub}\rm X{rcub}{dollar}Ga{dollar}\sb{lcub}\rm 1-X{rcub}{dollar}As and X equal to 0, 0.066, 0.21 and 0.40 for energies of 25, 50, 100 and 125 keV and doses of 3 {dollar}\times{dollar} 10{dollar}\sp{lcub}13{rcub}{dollar}, 1 {dollar}\times{dollar} 10{dollar}\sp{lcub}14{rcub}{dollar} and 1 {dollar}\times{dollar} 10{dollar}\sp{lcub}15{rcub}{dollar} atoms cm{dollar}\sp{lcub}-2{rcub}{dollar} have been measured. Primary ion beams of {dollar}\sp{lcub}16{rcub}{dollar}O{dollar}\sbsp{lcub}2{rcub}{lcub}+{rcub}{dollar} with a net energy of 8.0 keV and {dollar}\sp{lcub}133{rcub}{dollar}Cs{dollar}\sp+{dollar} with a net energy of 14.5 keV were used in this study and both positive and negative secondary ion intensities were measured.;This study found that while the {dollar}\sp{lcub}52{rcub}{dollar}Cr implant profile in Al{dollar}\sb{lcub}\rm X{rcub}{dollar}Ga{dollar}\sb{lcub}\rm 1-X{rcub}{dollar}As could be obtained by using the simple technique of voltage offset to discriminate against low energy molecular interferences, the same technique was ineffective with interferences to the {dollar}\sp{lcub}28{rcub}{dollar}Si species. In order to obtain depth distributions of {dollar}\sp{lcub}28{rcub}{dollar}Si, new computer software for the Cameca IMS-3f SIMS was developed with several innovations for high mass resolution depth profiling. Profiles with good dynamic range for {dollar}\sp{lcub}28{rcub}{dollar}Si were then obtained.;The negative and positive practical ion yields and sputter yields were observerd to vary linearly with aluminum concentration. Negative practical ion yields with Cs{dollar}\sp+{dollar} bombardment gave the smallest overall matrix effect for the species studied. The measured sputter yield for {dollar}\sp{lcub}16{rcub}{dollar}O{dollar}\sbsp{lcub}2{rcub}{lcub}+{rcub}{dollar} bombardment is close to predicted values and those of a previous study. The positive practical ion yields measured in this study differ from past studies which were performed without experimental conditions to limit molecular interferences. The measured projected range for {dollar}\sp{lcub}28{rcub}{dollar}Si implants agreed with theoretical calculations while those of {dollar}\sp{lcub}52{rcub}{dollar}Cr will provide the basis for comparison with theoretical predictions.
Recommended Citation
Robinson, William Harvey, "Aspects Of Sims Matrix Effects In Aluminum-gallium - Arsenide" (1988). Digitized Theses. 1712.
https://ir.lib.uwo.ca/digitizedtheses/1712