The Study Of Ion Implantation And Ohmic Contacts To SiC

In this paper, the characteristics of ion implantation and ohmic contact of SiC are deeply investigated. This thesis expatiates all the physics of the SiC ohmic contacts models, which have been developed by experiments, include metal-semiconductor schottky contact theory, Nn heterojunction and nn+ theory.Based on abundance of experiment literature, the reaction between the metal and semiconductor interface in the process of high temperature annealing has been studied. The carrier transportation mechanism of p-type and n-type SiC are investigated respectively, and the energy band model to explain ohmic contacts to p-type and n-type has been presented, that is gradual change heterojunction model. At last, the device simulator ISE TCAD has been used to validate the model with two dimension I-V characteristic simulation, and the unify model of SiC ohmic contacts to p-type and n-type SiC has been derived.Experiment has been design after the study of SiC ohmic contacts model. First, ion implantation technology, problems in the ion implantation and annealing cap in the annealing process after ion implantation have been introduced. Then the main steps of SiC ohmic contacts technology have been proposed. The experiment flow and result has been presented at the last, good result has been got from the experiment.The specific contact resistance obtained from measurement is an important parameter to evaluate the level of fabricates ohmic contacts. At the last of this thesis, some measurement methods for ohimc contacts specific contact resistance have been introduced. The rectangle transmission line model and some other test patterns have been studied and some comments are made for their comparison. Also, the error analysis about rectangle transmission line model and modify method have been discussed.