| 摘要 |
FIELD: semiconductor inspection technique, can be used for local inspection of deep-center parameters. SUBSTANCE: the method closest to the offered invention is the method of inspection of semiconductors based on relaxation spectroscopy of deep levels. This method consists in the fact that a voltage pulse is applied to the semiconductor barrier junction. As a result of action of this pulse of nonuniform voltage, relaxation processes of recharging of deep centers occur in the barrier junction that are indicated by variation of the barrier junction capacitance. Measurements are taken within the temperature range. The deep level parameters are calculated according to the dependences of the relaxation process parameters on temperature. The method of deep level relaxation spectroscopy makes it possible to determine all basic electrophysical parameters of deep centers, features a high sensitivity and energy resolution. The shortcoming of this method is the fact that it needs creation of barrier and ohmic contacts, as well as a low locality. In the offered method a semiconductor wafer under check is placed between two current-conducting plates, one of which is transparent, a non-equilibrium difference of potentials at the barrier junction is created by exposure of the semiconductor wafer to electromagnetic radiation through the transparent plate and by generation of photo-emf. Information on relaxation processes is picked off with the use of a capacitive coupling between the plates and surfaces of the semiconductor wafer. To provide the necessary locality, electromagnetic radiation is focused. If semiconductor wafers (for example, semiinsulating substrates) are homogeneous in thickness, a surface- semiconductor volume junction is used as the barrier junction. At implementation of the offered method it is most naturally to radiate the semiconductor wafer by square pulses of electromagnetic radiation of a fixed intensity, then to determine the amplitude and shape of the pulses at the current - conducting plates, and calculate the parameters of relaxation processes according to the parameters of the pulses at the plates. EFFECT: enhanced accuracy. 3 dwg |
