THE EFFECT OF HOT-ELECTRON INJECTION ON THE PROPERTIES OF FLICKER NOISE IN N-CHANNEL MOSFETS

We have studied the degradation of drain current and the properties of flicker noise in n-channel Lightly-Doped Drain (LDD) MOSFETs due to hot-electron injection. The two types of devices examined were shallow double-diffused drain and deep double-diffused drain MOSFETs. It was found that the flicker noise level is highly sensitive to hot-electron injection. The increase in flicker noise and drain current degradation in the shallow double-diffused drain devices were significantly more than the deep double-diffused drain devices, indicating improved hot-electron hardness in the latter. However, the pre-stressed flicker noise magnitudes in the deep double-diffused drain transistors were about two orders of magnitude higher than the shallow double-diffused drain transistors. This is possibly due to creation of defects during the high energy phosphorus implantation step in the fabrication of the deep drain junction.