Patent ID: 8217397

Claim:
A thin film transistor substrate having a semiconductor layer of a thin film transistor, a source electrode, a drain electrode, and a transparent conductive film, the source electrode and drain electrode comprising a thin film of Al alloy formed by patterning by dry etching, the thin film of Al alloy comprising 0.1 to 1.5 atom % of Ge, 0.1 to 3.0 atom % of at least one element selected from Ni and Co, and 0.1 to 0.5 atom % of at least one element selected from La and Nd, the source electrode and drain electrode being directly connected with the semiconductor layer comprising polycrystalline silicon or continuous grain polycrystalline silicon; wherein the ratio of the dry etching rate of the thin film of Al alloy to the dry etching rate of a thin film of pure Al is a value of 0.3 or higher.