HIGH PERFORMANCE THIN FILMS FOR MICROCIRCUITS (CAPACITORS).
Abstract
The report includes experimental results of the first twelve month's investigation of the fabrication of thin film hafnium - hafnium dioxide capacitors. Sputtered hafnium films were deposited on glass and anodized by both wet and plasma anodization processes. Wet anodization offers the advantage of larger range of forming voltage (up to 250V) as compared to the maximum forming voltage of about 60 for the plasmionic process. The temperature coefficient of capacitance has been measured to be +124 ppm/C over the temperature range from -196C to 300C, and as low as +40 ppm/C over smaller temperature ranges (+25C to 125C). Up to several hundred kHz, the capacitance is practically frequency insensitive and a Q of 50 has been measured at 22 MHz. Breakdown voltages frequently exceed the forming voltage by 50 percent or more. Life test data for wet anodized capacitors indicate changes less than 1% over several thousand test hours at room temperature of at 125C. The wet anodized capacitors exhibit small leakage currents (10-8 to 10-12 a/mm2) in the forward and backward direction, practically without preferred current flow in either direction. A dielectric constant of 45 was measured for the hafnium oxide. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1966
- Accession Number
- AD0635298
Entities
People
- Franz Huber
- Walter Witt