EVALUATION OF SEMICONDUCTOR TREATMENT PROCESS AND APPARATUS FOR THE SAME

摘要

PURPOSE:To realize non-contact measurement of an implanted ion quantity of low dosage implantation, an etched quantity and the like by a method wherein carriers are created near the surface of a semiconductor only and an electromagnetic wave which is influenced by the difference between the total number of carriers created continually by light application and the total number of carriers lost by recombination is detected. CONSTITUTION:A short wavelength light is applied to a treated Si wafer by a light source 1. The light is a continuous light or a pulse light whose pulse width is wider enough than the life-time of carriers of the substrate. The light passes through a chopper 2 and is divided by a half mirror 3. The separated laser beam is detected by a photodiode 7. The Si wafer 4 is so provided as to have its surface to be measured facing the light source 1 and accepting the light from the source 1. A microwave oscillator 5 and a microwave detector 6 are provided on the back side of the Si wafer 4. The microwave oscillator 5 emits the microwave against the wafer 4 and the microwave detector 6 detects the reflected wave of the microwave influenced by the excess carriers in the Si wafer 4 with a detection diode. The microwave is absorbed by the carriers in the Si wafer 4 but a degree of absorption is proportional to the carrier concentration. Therefore, the carrier concentration can be estimated by measuring the reflected light.