Abstract
A junctionless transistor with a reverse polarity structure includes a substrate, a semiconductor, a gate and a gate insulator. The substrate has a first polarity. The semiconductor is formed on the substrate and includes a drain terminal, a source terminal, and a channel segment disposed between the drain terminal and the source terminal. The gate covers one side of the channel segment away from the substrate. The gate insulator is formed between the gate and the channel segment. The semiconductor has a second polarity opposite to the first polarity. Through the substrate having the first polarity and the semiconductor having the second polarity opposite to the first polarity, the problem for leakage current can be improved and the device manufacturing costs will also be reduced.