Comments on The generation and Characterization of electron and Hole traps created by Hole injection during Low Gate voltage Hot-Carrier Stressing in n-MOS Transistors
Abstract
For original article by B.S. Doyle et al. see ibid., vol.37, p.1869-76, (Aug. 1990). In the above-titled paper the principal damage caused to n-MOSFETs during stress at low gate biases is claimed to be neutral electron trap generation in the gate oxide. These traps can supposedly be filled by injected electrons, when the transistor is biased at large drain and gate biases. When the generated electron traps are filled with electrons, a large degradation of current characteristics is observed. The commenters argue that no experimental evidence can be found to confirm this hypothesis. Using the data presented by Doyle et al. and in other studies the commenters show that the generation of neutral traps by injected holes is negligible. Neutral electron trap generation can, however, occur in MOSFETs when large oxide fields occur during operation. In reply, Doyle et al. argue that their normalization technique is correct, while that of the commenters leads to inconsistent results. After discussing several other points, they conclude that electron traps are created during channel hot-hole injection and must be taken into consideration in hot carrier lifetime estimates under AC conditions.