Characteristics of Polycrystalline Silicon Thin-Film Transistors with Electrical Source/Drain Extensions Induced by a Bottom Sub-Gate

Yu, Michael; Lin, Horng−Chih; Chen, Guo Hua; Huang, Tiao‐Yuan; Lei, Tan Fu

doi:10.1143/jjap.41.2815

Cited by 1 publication

(3 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The appearance of a hump in the subthreshold region as L Ͻ 1.5 m has been reported in our previous report. 14 The leakage path is believed to flow through the back-side surface of the channel layer, as illustrated in Fig. 6 ͑path 2͒.…”

Section: Resultsmentioning

confidence: 99%

“…The key process flow for fabricating the poly-Si TFTs with bottom sub-gate was described in detail in our previous work. 13,14 Briefly, a 100 nm n ϩ -poly-Si layer was deposited on an oxidized silicon substrate by low-pressure chemical vapor deposition ͑LPCVD͒. The doped poly-Si film was then patterned to form the fork-shaped bottom sub-gate.…”

Section: Methodsmentioning

confidence: 99%

“…Recently, we have proposed a novel TFT device with bottom sub-gate configuration. 13,14 In previous work we have explored and characterized the fabricated devices and shown that high device performance could be achieved using this structure. In this work, we further explore and compare the effects of plasma treatments in NH 3 or H 2 ambient on device characteristics.…”

mentioning

confidence: 99%

See 2 more Smart Citations

H[sub 2] and NH[sub 3] Plasma Passivation on Poly-Si TFTs with Bottom-Sub-Gate Induced Electrical Junctions

Lin

Huang

et al. 2003

J. Electrochem. Soc.

View full text Add to dashboard Cite

The effects of NH 3 and H 2 plasma passivation on the characteristics of poly-Si thin-film transistors ͑TFTs͒ with source/drain extensions induced by a bottom sub-gate were studied. Our results show that although significant improvements in device performance can be obtained by either passivation method, the NH 3 -plasma-treatment appears to be more effective in reducing the off-state leakage, subthreshold swing, and in improving mobility compared to H 2 plasma passivation. Furthermore, NH 3 plasma treatment is also found to be more effective in reducing the anomalous subthreshold hump phenomenon observed in nonplasmatreated short-channel devices. Detailed analysis suggests that all these improvements can be explained by the more effective passivation of traps distributed in both the front and back sides of the channel by NH 3 plasma treatment.Recently, polycrystalline silicon ͑poly-Si͒ thin-film transistors ͑TFTs͒ have received lots of attention as replacements for amorphous silicon TFTs in the switching elements of high-performance large-area active-matrix display and sensor systems. With their higher mobility, the peripheral driver circuitry can be integrated on the same substrate, which further improves system performance and reliability. 1,2 However, defects at the grain boundaries as well as inside the grains are known to cause device degradation, 3 resulting in poor device performance including low mobility and high offstate leakage current. 4,5 In order to obtain high-performance poly-Si TFTs, it is essential to reduce the trap density in the poly-Si channel. To this end, hydrogen plasma passivation is a well-known technique. 6,7 The atomic hydrogen can passivate defects in the poly-Si channel, thereby improving device characteristics. In addition, nitrogen-containing plasma treatments in combination with hydrogen ͑e.g., H 2 /N 2 mixture plasma, 8 nitrogen implantation with H 2 plasma, 9 preoxidation NH 3 annealing with H 2 plasma, 10 and NH 3 plasma 11 ͒ have also been shown to further improve the device performance. The additional nitrogen passivation and/or the enhanced hydrogen passivation effects in the presence of nitrogen are presumably responsible for the observed improved characteristics.Another approach for reducing the off-state leakage current is to use an electrical drain junction that is induced by a sub-gate. 12,13 It has been shown that with proper device structure design and operation conditions, the leakage current can be dramatically reduced without significantly compromising the drive current. Conventionally, 12 a top sub-gate configuration is used. Recently, we have proposed a novel TFT device with bottom sub-gate configuration. 13,14 In previous work we have explored and characterized the fabricated devices and shown that high device performance could be achieved using this structure. In this work, we further explore and compare the effects of plasma treatments in NH 3 or H 2 ambient on device characteristics. Figure 1 shows the cross-sectional and top views of the poly-Si TFT used i...

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation