NRA CHARACTERIZATION OF PRETREATMENT OPERATIONS OF SILICON

The aim of this study is to quantify the effects of different treatments generally used in the preparation of silicon for the rapid thermal processing (RTP). The atomic quantities of oxygen were determined by nuclear reaction analysis (NRA) using the O-16(d, p) O-17* nuclear reaction. This work can be divided in three parts: (1) A study of the resistance to oxidation as a function of time of bare silicon deoxidized with various chemical solutions. We show that silicon deoxidized by HF 4% and rinsed with ethanol exhibits the best oxidation resistance; only 4 x 10(15) atoms cm-2 of oxygen were found in the sample after a three-week air exposure. (2) A rapid thermal annealing (RTA) of bare silicon at atmospheric pressure, performed in a lamp-heated furnace under Ar and O2 at 700, 775 and 900-degrees-C for RTA times ranging from 10 to 90 s. The oxygen quantities measured by NRA show that under these conditions, the oxidation kinetic is the same for both ambients. (3) An investigation of the kinetic laws that control the rapid thermal oxidation of silicon (100). The treatment temperatures range from 1000 to 1150-degrees-C for durations varying from 0 to 90 s.