High-performance flexible thin-film transistors fabricated using print-transferrable polycrystalline silicon membranes on a plastic substrate

Abstract

Inexpensive polycrystalline Si (poly-Si) with large grain size is highly desirable for flexible electronics applications. However, it is very challenging to directly deposit high-quality poly-Si on plastic substrates due to processing constrictions, such as temperature tolerance and residual stress. In this paper, we present our study on poly-Si membranes that are stress free and most importantly, are transferrable to any substrate including a low-temperature polyethylene terephthalate (PET) substrate. We formed poly-Si-on-insulator by first depositing small-grain size poly-Si on an oxidized Si wafer. We then performed high-temperature annealing for recrystallization to obtain larger grain size. After selective doping on the poly-Si-on-insulator, buried oxide was etched away. By properly patterning the poly-Si layer, residual stress in the released poly-Si membranes was completely relaxed. The flat membrane topology allows the membranes to be print transferred to any substrates. High-performance TFTs were demonstrated on the transferred poly-Si membranes on a PET substrate.

Mechanically flexible optically transparent silicon fabric with high thermal budget devices from bulk silicon (100)

“…Although transparent plastic substrates provide interesting and cost-effective solutions, two fundamental issues prevent its full potential: (i) inherent low mobility makes it unsuitable for high performance computation applications and (ii) incompatibility with high thermal budget processes which have been leveraged for many modern silicon based diversified technologies. Even then, flexible thin film transistors, displays, photovoltaic, sensors, photodetectors are fabricated through wafer thinning technologies such as back-grinding and carrier techniques 28 , or through physical transfer of thin semiconductor segments (as large as 450 m x 45 m or 200 m x 7 cm) or membranes onto plastic substrates [29][30][31] . For example J. Rogers et.…”

“…al. has shown high performance poly-Si TFT with pre-transfer doping, the challenges remain with devices sizes and full fabrication [29][30][31][32][33][34][35] .…”

Silicon nanomembranes for high-performance flexible photonic interconnects and devices

“…Using such nanomembranes, new properties of nanomembranes for use in the flexible electronics and photonics have been studied and explored [3][4][5][6][7][8][9][10][11][12]. Among all transferrable single crystal semiconductors, silicon nanomembrane (SiNM) is one of the most promising materials because it possesses not only high carrier mobility and mechanical durability, but also optical transparency in the near infrared region, thus making it suitable for developing high performance flexible optoelectronic devices.…”

On the bending characterization of flexible radio-frequency single-crystalline germanium diodes on a plastic substrate

“…However, these materials suffer from their relatively low carrier mobilities and are thus only suitable for low-or moderate-speed applications. 2,3,6 More applications that require higher operation speed or even radiofrequency (rf) operation capability are highly desirable, examples including long-distance rf identifications (RFIDs), remote communication applications, etc. [2][3][4][5] In addition, recently emerging healthcare applications such as epidermal electronics, wearable electrophysiological monitoring devices, therapy of motion-related neurological diseases, etc., are one of the important applications of high-performance flexible electronics.…”