Chapter 3 The GaAs Field-Effect Transisitor

Electrical Properties of Thin GaAs Films Deposited by Sputtering.

“….7 x l0 18 /cm 3 for sample 11-1 , which is also 100% Si doped . The reason for the difference is that Hall effect measurements determine the density of free carriers and the capacitance measurements determine the density of charge centers in the film [ 9 ] . The difference is due to the density of traps , assuming complete donor ionization , which is to be expected for silicon in GaAs .…”

Electron Device Contact Studies.

“…The method used for this program is attributed to Schockley and known as the transfer length method [19].…”

“…Yu [15] used this method to investigate contacts made to Si, and Hower, et al [19] used it for As/In/Ge contacts to GaAs. The basic contact structure is shown in Figure 4.…”

“…This would not allow the fabrication of islands so another structure was necessary. Other investigators [19], have used mesa etched structures when investigating similar contact structures. However, due to the ease with which GaAs can be scribed and the smoothness of the resulting edge cleave, it was felt that contact structures fabricated with p-n junction isolation only on the bottom and then scribed apart into rectangles would be sufficient.…”

C-V profiling of GaAs FET films

“…- [4] is probably the single most important method used to characterize GaAs films grown on semi-insulating substrates for MESFET [ 5 ] applications. The reasons for the wide acceptance of this measurement technique are clear: 1) many common metals form excellent Schottky barriers on GaAs without elaborate surface preparation, passivation, or guarding; 2) one relatively simple measurement provides the material parameters of greatest interest to the crystal grower and de- Wiley and Miller emphasized that when profiling GaAir FET films one must not automatically assume that the mea.…”