The 1/f Noise Performance for TFTs Fabricated in Three TFT Technologies:Monocrystalline Silicon on Glass, Low Temperature Polysilicon on Glass, and Silicon on Insulator

摘要

Thin film transistors (TFTs) form the building blocks for display pixel drivers and imaging sensors. For sensing systems, the TFT intrinsic low frequency noise performance is one of the primary factors limiting dynamic range and signal-to-noise ratio (1). Recently, a low temperature monocrystalline thin-film silicon on glass (Corning? SiOG) CMOS process technology has been developed to offer improved performance for display driver electronics (2) (3). The SiOG process technology has been designed to minimize the number of mask layers and processing steps in order to reduce cost and increase display panel yield. An NMOSFET is built in a thin-film p-type substrate and operates as a conventional inversion channel device with n+ source and drain regions. The PMOSFET is created in the same p-type thin-film substrate with p+ source and drain regions. The flatband voltage can be adjusted to equal the negative magnitude of the NMOS threshold voltage producing a fully depleted thin-film channel in the PMOSFET with zero gate voltage. PMOSFET channel conduction results by operating the device in accumulation, providing complementary MOS structures in a single Fermi-level process technology. In this paper, the 1/f noise performance of SiOG devices is compared to