HIGH PERFORMANCE THIN FILMS FOR MICROCIRCUITS.
Quarterly progress rept. no. 6, 1 Jun-31 Aug 66,
RADIO CORP OF AMERICA SOMERVILLE N J DEFENSE MICROELECTRONICS
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A new sputtering system was designed and built with a vertical arrangement of electrodes to permit deposition of metal films free from pin holes. A hexagonally shaped substrate holder, which rotates to six different positions, allows performance of five sputtering runs without breaking the vacuum. A sputtering rate as high as 1500 Amin was achieved. A number of thin film hafnium dioxide capacitors were fabricated onto silicon substrates. Three different approaches were tested 1 Silicon substrates passivated with a thermally grown oxide are used without making electrical contact between the hafnium film and the silicon substrates. 2 Windows etched into the SiO2 layer established ohmic contact between the silicon substrate P-type and the hafnium film which is partically converted into dielectric hafnium dioxide. 3 Hafnium metal completely converted into oxide. In another series of experiments, metal oxide semiconductor transistors were fabricated and studied with anodically formed HfO2 used as the gate insulator. A surface state density, N sub ss, of 13 x 10 to the 11th power statessq cm was determined by capacitance - voltage measurements. This performance is comparable to thermally grown SiO2. The main advantage in using HfO2 for gate insulators are the high dielectric constant and the good dielectric properties of anodically grown oxides. Author
- Electrical and Electronic Equipment