Wafer scale fabrication of carbon nanotube thin film transistors with high yield

Abstract

Carbon nanotube thin film transistors (CNT-TFTs) are promising candidates for future high performance and low cost macro-electronics. However, most of the reported CNT-TFTs are fabricated in small quantities on a relatively small size substrate. The yield of large scale fabrication and the performance uniformity of devices on large size substrates should be improved before the CNT-TFTs reach real products. In this paper, 25 200 devices, with various geometries (channel width and channel length), were fabricated on 4-in. size ridged and flexible substrates. Almost 100% device yield were obtained on a rigid substrate with high out-put current (>8 μA/μm), high on/off current ratio (>105), and high mobility (>30 cm2/V·s). More importantly, uniform performance in 4-in. area was achieved, and the fabrication process can be scaled up. The results give us more confidence for the real application of the CNT-TFT technology in the near future.

Recent advancements in transparent carbon nanotube films: chemistry and imminent challenges

“…Recently, the advancement of solution-prepared high clearness SWCNT substances [233,234], uniform system class CNT sheet including exact tube density is possible upon large area supports [235][236][237][238], that promotes the advancement of high-performance CNT thin-film transistors (CNT-TFTs). TFTs are essential electronic components, for example, screen panels, Radio-frequency identification (RFID), Printed circuit board (PCB), electric sensors, and so on.…”

Chirality‐Enriched Carbon Nanotubes for Next‐Generation Computing

“…A total of 25 200 SWCNT FETs with various geometries were fabricated using standard CMOS processing, achieving nearly 100% yield and narrow distributions in key performance metrics (e.g., current density, ON/ OFF ratio, threshold voltage, and mobility) over the entire substrate area. [109] To further test the wafer-scale compatibility of SWCNTs with complex fabrication designs, 3D fin-structured SWCNT FETs were fabricated on a rigid 8 in. Si substrate.…”

Origins of the variability of the electrical characteristics of solution-processed carbon nanotube thin-film transistors and integrated circuits

“…5 CNT TFTs are also advantageous in simple fabrication processes such as solution processing. [6][7][8][9] To date, signicant efforts have been made to realize highperformance CNT TFTs, 10,11 medium-scale integrated circuits (ICs) 12 and random-access memory 13 based on CNT TFTs, and large-scale complementary circuits using CNT and oxidesemiconductor TFTs. 14 However, device-to-device variation of the electrical characteristics remains an obstacle to their practical application.…”

“…Several studies on the characteristic variations of s-CNT-based TFTs have been reported on so far. 8,24,25 Ohmori et al reported that the characteristic variations can be reduced by using shorter CNTs, 25 although the carrier mobility may be degraded due to the increase in the number of CNT-to-CNT junctions in the current path. Tian et al achieved wafer-scale fabrication of CNT TFTs with high yield on a 4-inch Si substrate by drop coating.…”