Radiation hardened p-surface channel CCD's
A process for total dose hardening of surface p-channel CCD's with overlapping polysilicon gates has been developed by optimizing the process steps associated with the gate oxides and polysilicon gates. 16-bit shift registers fabricated with this process can be operated up to 1 x 10/sup 6/ rads (Si) with threshold voltage shifts of less than or equal to 2 V for the buried gates, and less than or equal to 1.5V for the surface gates on the best devices fabricated. The charge transfer efficiency for the devices with -10V gate bias during irradiation is unchanged after 1 x 10/sup 6/ rads (Si), but drops to 0.999 for the devices with OV gate bias during irradiation. The average dark current increases to only 1.75 times the initial value after 1 x 10/sup 6/ rads (Si) for devices with -10V gate bias during irradiation, and to 4 times the initial value for the devices with OV gate bias. No additional dark current spikes are observed up to 1 x 10/sup 6/ rads (Si). These results represent a very large improvement in hardness over typical CCD's.
- Research Organization:
- Hughes Aircraft Co., Newport Beach, CA
- OSTI ID:
- 7256743
- Journal Information:
- IEEE Trans. Nucl. Sci.; (United States), Journal Name: IEEE Trans. Nucl. Sci.; (United States) Vol. NS-23:6; ISSN IETNA
- Country of Publication:
- United States
- Language:
- English
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