We have fabricated high quality, dielectric Ga2O3 thin films. The film
s with thicknesses between 40 and 4000 angstrom were deposited by elec
tron-beam evaporation using a single-crystal high purity Gd3Ga5O12 sou
rce. Metal-insulator-semiconductor (MIS) and metal-insulator-metal str
uctures (MIM) were fabricated in order to determine dielectric propert
ies, which were found to depend strongly on deposition conditions such
as substrate temperature and oxygen pressure. We obtained excellent d
ielectric properties for films deposited at substrate temperatures of
40-degrees-C with no excess oxygen and at 125-degrees-C with an oxygen
partial pressure of 2X10(-4) Torr. Specific resistivities rho and dc
breakdown fields E(m) of up to 6X10(13) OMEGA cm and 2.1 MV/cm, respec
tively, were measured. Static dielectric constants between 9.93 and 10
.2 were determined for these films. Like in other dielectrics, the cur
rent transport mechanisms are found to be bulk rather than electrode c
ontrolled.