Ion implanted voltage variable capacitors and related processing

Ion implantation is presently being absorbed by the semiconductor industry as a complementry production process compatible with more established techniques. At KEV implantation has been combined with shallow diffusion and silane epitaxy techniques to develop and manufacture voltage variable capacitors for VHF, UHF and AM applications in consumer electronics, and commercial and military communications equipment. Based on the precise control and variability of the implantation process, these tuning diodes have been designed with predetermined hyperabrupt structures giving a high minimum operating voltage for minimum signal distortion, minimum tuning voltage spread, and high Qs. The reproducibility of implantation is reflected in the resulting small spread in diode characteristics and associated close tracking in large lots.