EFFECT OF PROCESS VARIATIONS ON AN OTFT COMPACT MODEL PARAMETERS

We have studied the effect of some of the possible deviations on the values of the extracted parameters of a specific OTFT model, considering OTFTs designed using P3HT as semiconductor layer, PMMA as insulator, bottom gate, and top gold contacts. Specifically, we have studied the influence of misposition or misalignment of the masks, the effect of imperfections of etching, and the effect of variations on the layer deposition process. These effects have been simulated using the Silvaco Athena software, and they have been modeled as horizontal shifts of the etching windows and variations of the layers thickness. Once the devices were defined, they were simulated using Silvaco Atlas, and parameter extraction was performed using a specifically developed algorithm. We have found a strong correlation among some of the physical parameters and the model parameters that may offer useful insight for process optimization. Moreover, strong correlations have been found also among the model parameters. We have used these results to develop a Monte Carlo model, suitable for statistical circuit simulation.