Buried P-layer Research Articles

Below 10 ps/gate operation with buried p-layer SAINT FETs

GaAs SAINT FETs with a p-layer buried under the active layer have achieved below 10 ps/gate (9.9 ps/gate) operation for the first time in semiconductor devices. The p-layer formed by Be+ implantation is completely depleted by the built-in potential. It has successfully alleviated the short channel effects without increasing parastic capacitance.

Transient Radiation Effects at X-Band in GaAs FETs and ICs

Transient radiation effects following 20-60 ns electron pulses were measured in GaAs FETs and ICs operating at X-band. Long-term transients in RF output power and drain current were observed in all devices and ICs except FETs fabricated with a buried p-layer. Only the prompt (20 ns) photocurrent response was observed in FETs with a buried p-layer. The long-term transients are explained by a model of substrate trapping and backgating.

Long-term transient radiation-resistant GaAs FET's

The amplitude of long term, pulse-radiation-induced transients in ion implanted GaAs FET's has been reduced by up to two orders of magnitude by the addition of a deep buried p-layer beneath the active n-layer. The p-layer was formed by ion implantation of Be to depth of 0.8 µm below the Si implanted n-active channel. Backgating was also greatly reduced as indicated by a much smaller amplitude transient response following application of a positive gate pulse and by the absence of light sensitivity and looping in the current/ voltage (I-V) characteristics.

Reduction of Long-Term Transient Radiation Response in Ion Implanted GaAs FETs

The long-term transient radiation response in ion implanted GaAs FETs induced by flash x-ray or electron pulses has been reduced by the incorporation of a deep buried p-layer beneath the active n-layer. Reductions in the change in drain current of up to two orders of magnitude were measured in FETs with the buried p-layer compared to FETs with only an n-implanted channel following a 100 rad x-ray pulse. This improvement in radiation tolerance is attributed to shielding of the active n-layer by the conducting p-layer from the effects of radiation induced trapped substrate charge.