High electron mobility transistors on plastic flexible substrates

Abstract

The double-flip transfer of indium phosphide ͑InP͒ based transistors onto plastic flexible substrates was demonstrated. Modulation doped field effect transistor layers, epitaxially grown on InP bulk substrates, were transferred onto sapphire using a masked ion-cutting process. Following layer transfer, transistors were fabricated at low temperatures ͑Յ150°C͒. The device structure was then bonded to flexible substrate, and laser ablation was used to separate the initial bond. The transferred transistors were characterized and exhibited high field-effect mobility ͑ average ϳ 2800 cm 2 V −1 s −1 ͒.Due to bendability, toughness, and light weight, flexible substrates can be useful in a wide variety of applications such as smart clothing, energy panels, biosensors, and flexible displays. 1 To form circuit elements in these applications, thin film transistors are required. Amorphous silicon and organic semiconductors are commonly used because their low deposition temperatures are compatible with plastic substrates such as polyethylene naphthalate ͑PEN͒, which has temperature tolerance Ͻ200°C. 2 The low carrier mobility of these materials ͑typically Ͻ10 cm 2 V −1 s −1 ͒; however, limits their potential for use in high-speed applications. 3,4 Ion-cutting has proven useful for integration of singlecrystal semiconductors with alternative substrates at various temperatures, depending on implant and annealing conditions. 5 Ion-cutting involves proton ͑H + ͒ implantation, at high doses ͑ϳ10 17 cm −2 ͒ into a donor, followed by wafer bonding of the donor to an acceptor substrate. Upon annealing, the hydrogen segregated to the implantation-induced damage region nucleate into gas bubbles, resulting in thinfilm layer separation onto the acceptor. 6 A key benefit to ion-cutting is that the donor can be reused after the process.Recently, indium phosphide ͑InP͒ transfer onto flexible substrate was demonstrated in a double-flip process involving ion-cutting and adhesive bonding. 7 A major drawback to the process is that the implantation damage leads to electrically active defects which are difficult to eliminate. Bulk characteristics cannot be fully restored even after annealing to 600°C. 8 In previous experiments, we have shown that devices fabricated on ion-cut InP layers either function with undesired characteristics ͑photodetectors͒ or do not function at all ͑transistor͒. 9,10Masked ion-cutting can mitigate implantation damage by protecting critical regions from impinging ions with a thick, removable mask. 11 These protected areas are transferred along with adjacent implanted areas during exfoliation. In the masked ion-cutting of ͑100͒ InP, protected areas transfer with pyramidal protrusions associated with the exfoliation process, which can be removed following transfer. 12 In this letter, we used masked ion-cutting in a double-flip transfer to enable integration of InP-based high electron mobility transistor ͑HEMTs͒ on PEN substrates.Modulation doped field effect transistor ͑MODFET͒ layers were grown on InP via metal organic vap...

Microwave performance of 100 nm-gate In0.53Ga0.47As/In0.52Al0.48As high electron mobility transistors on plastic flexible substrate

“…6 In order to reach better electrical performance, the use of InAlAs/InGaAs high electron mobility transistor (HEMT) integrated into the polyimide substrate (Kapton) and embedded into thin-film micro-strip (TFMS) lines, is proposed in this letter. It is to be noted that only one paper dealing with the fabrication process of large 50 lmgate InGaAs/InAlAs HEMT on flexible substrate (HEMT-FS) 7 has been published. If the electrical static performance was reported, dynamic performance was missing, which is among the main objective of this letter.…”

Recent advances in single crystal narrow band-gap semiconductor nanomembranes and their flexible optoelectronic device applications: Ge, GeSn, InGaAs, and 2D materials

“…Recently, InGaAs NMs were developed for applications in optoelectronic devices, such as PDs, 83,84 LEDs, 85 and field effect transistors. 86 For example, D. Fan et al demonstrated a thinfilm InGaAs p-i-n PD array fabricated on a thin and flexible polyimide Kapton substrate.…”