イオン打込みしたMOS構造の性質

抄録

Changes in gate threshold voltage (V_T), carrier mobility (μ), and low-frequency-noise characteristics have been investigated for n-channel MOSFET's, into whose channel region ¹¹B⁺, ²⁷Al⁺, ²⁸Si⁺ and ³¹P⁺ ions were implanted through their gate oxide film.
In case of Si implantation, a slight decrease in μ still remained after 15min. anneal at 950°C, while no significant change was observed in V_T or in noise characteristics. Introduction of acceptor ions resulted in a substantial decrease in μ, and an increase in low-frequency noise level. The shift in V_T was found to be proportional to implantation dose up to 10¹² cm^-2 in case of B⁺ and P⁺ implantation.
It is possible to detect the effct of radiation damages from the changes in V_T of MOS-FET's. From the annealing behavior of Si⁺ implanted MOSFET, the activation energy of annihilation of such radiation damages was obtained to be 0.35 eV.