Direct lateral profiling of both interface traps and oxide charge in thin gate MOSFET devices

Abstract

A simple method has been developed to measure the localized hot carrier damage in scaled thin-gate MOSFET's. Lateral distributions of both interface traps and oxide charge can be derived directly from experimental charge pumping results without numerical simulation.

Device scaling effects on hot-carrier induced interface and oxide-trapped charge distributions in MOSFETs

“…The simulation-based methods [22]- [26] are unsatisfactory due to the requirement of the knowledge of exact device structure and doping profiles. The direct methods either need separate neutralization steps and are complex in nature [27], [28] or need iterative numerical differentiation susceptible to measurement noise [29]. Moreover, it has recently been shown [31] that the methods [27]- [30] furnish incorrect spatial position of the damage profiles.…”

“…The direct methods either need separate neutralization steps and are complex in nature [27], [28] or need iterative numerical differentiation susceptible to measurement noise [29]. Moreover, it has recently been shown [31] that the methods [27]- [30] furnish incorrect spatial position of the damage profiles. To overcome the existing difficulties, we have recently proposed a new method [32] which does not require computer simulation, iteration or neutralization, is more immune to measurement noise (by avoiding experimental data differentiation), and provides an accurate distribution of and created during hot-carrier stress.…”

A comprehensive study of hot-carrier induced interface and oxide trap distributions in MOSFETs using a novel charge pumping technique

“…These methods are unsatisfactory due to the requirement of exact device structure and doping profiles. The direct methods [9]- [11] employ variable amplitude gate pulse to vary the CP area and calculate the position of the CP edge from prestress measurements C. R. Viswanathan is with the Department of Electrical Engineering, University of California, Los Angeles, CA 90095-1594 USA.…”

“…Correction to the prestress CP edge for charges associated with the generated defects and the separation of and distributions are performed either by neutralization of by a brief carrier injection of the opposite type [9], [10], or by an iterative correction scheme [11]. However it has recently been shown [13] that the existing methods [9]- [12] do not take into account the increase in CP current due to the increased energy zone of recombination (with increased gate pulse amplitude) and hence furnish incorrect CP edges and damage profiles. Moreover, the intermediate carrier injection techniques [9], [10] need separate experimental tools to monitor complete neutralization, and hence in general are complex in nature.…”

“…However it has recently been shown [13] that the existing methods [9]- [12] do not take into account the increase in CP current due to the increased energy zone of recombination (with increased gate pulse amplitude) and hence furnish incorrect CP edges and damage profiles. Moreover, the intermediate carrier injection techniques [9], [10] need separate experimental tools to monitor complete neutralization, and hence in general are complex in nature. On the other hand, the iterative scheme [11], being dependent on repetitive differentiation of experimental data, is highly susceptible to measurement noise and may give rise to convergence problems.…”