A manufacturing sensitivity analysis of 0.35 μm LDD MOSFET´s

Fundamental to successful manufacturing of integrated circuits is the achievement of sufficient control in all process steps to realize, with very high yield, fully functional circuits whose performance and reliability conform to pre-determined standards. Towards this end, it is increasingly necessary to relate in a quantitative manner the sensitivity of the electrical performance of the final devices and circuits to variations in structural parameters and doping profiles, which in turn can be related to process and tool performance variations. In this paper, we describe the results of an analysis performed to quantify the sensitivity of the electrical parameters of a 0.35 μm LDD MOSFET to variations in the doping and structural parameters of the device that are anticipated in manufacturing. A central-composite design was used to develop second-order models for six key device electrical parameters. The resulting models are manifested as second-order equations relating the device electrical parameter variations to random variations in seven key device structure and doping parameters. This set of equations thus allows one to understand quantitatively the source and nature of the device electrical parameter variations. A simple Monte Carlo approach is applied to predict the statistical distributions of the key device electrical parameters which result from the random manufacturing variations in the structure and doping parameters by using the quantitative relationships developed in this paper