PLASMA ENHANCED BEAM DEPOSITION OF THIN FILMS AT LOW TEMPERATURES.

A plasma enhanced beam deposition technique for thin films is discussed. It is shown that thin films of tailored stoichiometry or amorphous layers can be easily deposited in the temperature range (30-250 degree C). The technique uses a combination of active atomic or molecular beams generated by charged particles or photons. Films of SiO//2, Al//2O//3, ZrO//3, silicon oxynitride, NbN, etc. , have been deposited on metals, semiconductors, and insulators. The interfaces between the deposited films and the substrates are extremely sharp, and no native growth of oxides of nitrides occurred on the substrate surfaces during film deposition. Film thickness and composition can be precisely controlled by optical monitoring techniques. For instance, the physical properties of the deposited SiO//2 at 100 degree C is nearly identical to that of thermal oxides grown on Si at 1100 degree C. The deposited SiO//2 has an electrostatic breakdown field strength of about 5 multiplied by 10**6V/cm, and 1 MHz C-V curves show a hysteresis of 50 mV at a sweep rate of 100 mV/s. The fixed charge density is 3. 5 multiplied by 10**1**1 cm** minus **2. The advantages of this process for depositing Al//2O//3 on InP, GaAs, and Si are discussed. Utilizing the low temperature nature of the technique, patterns of mu -width SiO//2 features have been made using photoresist masked substrates and the lift-off technique. Finally, it is proposed that epitaxial growth of compound films should also be possible under UHV conditions.