Differential Reflectance as AN Analytical Tool for the Study of Microelectronic Processed Samples
Abstract
Microelectronic technology continues to decrease the size of devices and therefore the dimensions allowed for each process step involved. The ability to measure small differences and thin surface films is very important in this field. Differential reflectance, DR, is a non -destructive technique which has been shown to be sensitive to small differences at the surface. The use of DR to study the process of ion implantation, and the related areas of preamorphization and annealing, is the focus of this dissertation. DR has been shown to be sensitive to damage layers formed by ion implantation as witnessed by changes in the interband transition peaks and also to the presence of interference bands for some film covered substrates. High concentrations of implanted ions, such as the case of preamorphization, cause shifts in the interband transitions. The effectiveness of temperature in the removal of crystalline and amorphous damage was also discernable from DR spectra which showed good agreement with information gained by transmission electron microscopy, TEM. DR was sensitive to small amounts of crystalline defects not discernable by TEM. Information found by DR studies is in good agreement with TEM and spectroscopic ellipsometry, SE. Although SE is usually considered superior as a precise optical technique, respectable sensitivity and simplicity makes DR a suitable technique for in-situ comparative applications where a qualitative assessment of a sample with a standard is sufficient. Although TEM obtains information differently, it is shown that DR can sometimes reach the same conclusions and does not require painstaking sample preparation. Also, a new DR arrangement is described that would allow more versatile in-situ studies.
- Publication:
-
Ph.D. Thesis
- Pub Date:
- 1992
- Bibcode:
- 1992PhDT.......208B
- Keywords:
-
- ION BEAM DAMAGE;
- Chemistry: Analytical; Engineering: Materials Science; Physics: Condensed Matter