Using dual plasma treatment to improve electrical characteristics and reduce flicker noise of high-κ HfO2 LTPS-TFTs. (September 2015)

• Record Type: Journal Article
• Authors: Chang, Kow-Ming; Huang, Bo-Wen; Wu, Chien-Hung; Deng, I-Chung; Chang, Ting-Chia; Lin, Sheng-Chia
• Is Part Of: Solid-state electronics. Volume 111(2015)
• Page Start: 7
• Page End: 11
• Publication Date: 2015-09
• Subjects: Dual plasma treatment -- LTPS-TFTs -- High-κ metal gate -- Flicker noise; Semiconductors -- Periodicals; Semiconducteurs -- Périodiques; 621.38152
• DOI: 10.1016/j.sse.2015.03.017
• Languages: English
• ISSNs: 0038-1101

Abstract

Highlights: This study demonstrates excellent electrical characteristics of high-κ LTPS-TFTs after dual plasma treatment (DPT). Flicker noise can be effectively suppressed after DPT. High performance high-κ LTPS-TFTs with DPT is suitable for major AMLCD applications on SOP technology. Abstract: This study demonstrated the application of a dual plasma treatment to low-temperature polycrystalline-silicon thin-film transistors (LTPS-TFTs) comprising a self-aligned phosphorus implantation source and drain, high-κ HfO2 gate dielectric, and aluminum metal gate. The dual plasma treatment involves a pre-deposition CF4 plasma treatment at a high-κ/poly-Si interface and post-deposition N2 plasma treatment at a high-κ HfO2 gate dielectric; this treatment enables reducing the interface-trap-state defects at the high-κ/poly-Si interface, grain boundary traps in the poly-Si channel film, and oxygen vacancy V o in the high-κ HfO2 gate dielectric. Thus, LTPS-TFTs with dual plasma treatment demonstrate excellent electrical characteristics such as threshold voltage, subthreshold swing, transconductance, driving current, and on/off current ratio. Flicker noise, also referred to as 1/f noise, caused by fluctuations of carriers transported in the grain boundary and the trapped carriers per unit oxide volume ( N t ) can be suppressed. Therefore, high performance LTPS-TFTs subjected to dual plasma treatment can be appropriately applied to active matrix liquid phase-crystal display on system-on-panel technology.