Patent ID: 8912536

Claim:
A method of manufacturing an oxide transistor, the method comprising: forming a gate on a substrate; forming a gate insulating layer to cover the gate; forming a channel layer on the gate insulating layer; and forming a source electrode to contact a first end portion of the channel layer, and a drain electrode to contact a second end portion of the channel layer; wherein the forming of the channel layer includes, forming a first material layer and a second material layer sequentially on the gate insulating layer, the first material layer includes hafnium-indium-zinc-oxide (HfInZnO) and has a first electrical conductivity, the second material layer includes hafnium-indium-zinc-oxide (HfInZnO) and has a second electrical conductivity that is lower than the first electrical conductivity, the first material layer is closer to the gate than the second material layer, the first material layer and the second material layer have different metal composition ratios, and a zinc content of the second material layer is greater than a zinc content of the first material layer, the zinc content of the second material layer is between about 50 at % and about 87 at % based on the metallic components of the second material layer.