Hyuga Taniguchi, Kei Oya, Takeo Nakano, Masayoshi Nagao, Hisashi, Ohsaki, Katuhisa Murakami
IEICE technical report. Electron devices, Oct 24, 2018, The Institute of Electronics, Information and Communication Engineers (IEICE), Japan
Spindt-type emitter is one of the vacuum electron sources prepared by semiconductor manufacturing technologies. On its fabrication, microcavities with a hole on their ceiling are prepared on a Si substrate, and an emitter material (e.g. Mo) is deposited through the hole inside of the cavity. Conventionally, the emitter cathode material has been deposited by using vacuum evaporation. This method, however, has difficulties in large area manufacturing and requires substrate heating to alleviate the tensile stress in the deposited films. In this study, we applied a high power pulsed magnetron sputtering (HPPMS) technique which can ionize the depositing particles and can control their direction and incidence energy. We have demonstrated the Mo emitter preparation at room temperature, but the reversed (compressive) stress frequently resulted in the delamination of the coatings and hindered the stable production of the device. In this study, we used Kr as a discharge gas to suppress the compressive stress of Mo films and compared the results with those prepared by conventional Ar gases. In addition, we applied various negative substrate voltages and investigated its effect on the film stress and the emitter structure.