Monte carlo simulation of the two-dimensional site percolation problem for designing sensitive and quantitatively analyzable field-effect transistors

To investigate the effect of charged substances on the properties of ion-sensitive field-effect transistors (ISFETs), the site percolation property of a finite-size two-dimensional square-lattice system was analyzed by Monte Carlo simulation. We found that the variation in the aspect ratio (width/length) of the channel leads to two important features: the sensitivity of the ISFET is enhanced with a decrease in width and/or an increase in length; however, ISFET having a rather wide and/or short channel produces the best performance in quantitative analysis. The results of this study would be applicable to the design of an ultrasensitive and quantitatively analyzable ISFET.