US Patent 9653617 Multiple junction thin film transistor

A multiple junction thin film transistor (TFT) is disclosed. The body of the TFT may have an n+ layer residing in a p− region of the body. The TFT may have an n+ source and an n+ drain on either side of the p− region of the body. Thus, the TFT has an n+/p−/n+/p−/n+ structure in this example. The n+ layer in the p− region increases the breakdown voltage. Also, drive current is increased. The impurity concentration in the n+ layer in the p− body and/or thickness of the n+ layer in the p− body may be tuned to increase performance of the TFT. In an alternative, the body of the TFT has a p+ layer residing in an n− region of the body. The TFT may have a p+ source and a p+ drain on either side of the p− region of the body.