Contactless Semiconductor Mobility Determination
Original Publication Date: 1985-Feb-01
Included in the Prior Art Database: 2005-Feb-18
The electrical properties of semiconductors, such as GaAs and GaAlAs, in conventional wafer sizes can be evaluated by establishing an area averaged mobility by measurement of magnetoconductance at microwave frequencies in accordance with the expression describing the conductivity at magnetic field B compared with B=0 where m is the mobility whose value is desired. A reflectometer is provided where the change in reflection with magnetic field is small compared to the total signal so that the reflected signal is proportional to the power absorbed, which, in turn, is proportional to s. The waveguide sample holder is designed to allow fast nondestructive mount of large wafers. An adjustable short behind the sample is used to allow impedance compensation for any sample sheet conductivity.