Patent ID: 7125758

Claim:
A method of PECVD depositing an a-SiN x :H dielectric film useful in a TFT device as gate dielectric, when a series of TFT devices are arrayed over a substrate having a surface area larger than about 1 m 2 , said method comprising: depositing said a-SiN x :H dielectric film over a substrate which is at a temperature ranging from about 120° C. to about 340° C.; depositing said a-SiN x :H dielectric film at a process pressure which ranges between about 1.0 Torr to about 2.0 Torr; depositing said a-SiN x :H dielectric film from precursors including N 2 , NH 3 , and SiH 4, and wherein a component ratio of NH 3 /SiH 4 ranges from about 5.3 to about 10.0, a component ratio of N 2 /SiH 4 ranges from about 5.5 to about 18.7, and a component ratio of N 2 /NH 3 ranges from about 0.6 to about 2.3; and applying a plasma to a mixture of said precursors, so that the plasma density in a process chamber in which said a-SiN x :H dielectric film is deposited ranges between about 0.2 W/cm 2 and about 0.6 W/cm 2 .