High-performance flexible BiCMOS electronics based on single-crystal Si nanomembrane

Jung-Hun Seo,Munho Kim,Zhenqiang Ma,Kan Zhang,Weidong Zhou

doi:10.1038/s41528-017-0001-1

Abstract

In this work, we have demonstrated for the first time integrated flexible bipolar-complementary metal-oxide-semiconductor (BiCMOS) thin-film transistors (TFTs) based on a transferable single crystalline Si nanomembrane (Si NM) on a single piece of bendable plastic substrate. The n-channel, p-channel metal-oxide semiconductor field-effect transistors (N-MOSFETs & P-MOSFETs), and NPN bipolar junction transistors (BJTs) were realized together on a 340-nm thick Si NM layer with minimized processing complexity at low cost for advanced flexible electronic applications. The fabrication process was simplified by thoughtfully arranging the sequence of necessary ion implantation steps with carefully selected energies, doses and anneal conditions, and by wisely combining some costly processing steps that are otherwise separately needed for all three types of transistors. All types of TFTs demonstrated excellent DC and radio-frequency (RF) characteristics and exhibited stable transconductance and current gain under bending conditions. Overall, Si NM-based flexible BiCMOS TFTs offer great promises for high-performance and multi-functional future flexible electronics applications and is expected to provide a much larger and more versatile platform to address a broader range of applications. Moreover, the flexible BiCMOS process proposed and demonstrated here is compatible with commercial microfabrication technology, making its adaptation to future commercial use straightforward.

Highlights

In traditional microelectronics, complementary metal-oxide semiconductor (CMOS) transistors have clear advantages over their counterpart, bipolar transistors, such as lower power dissipation and higher packing density
We demonstrate flexible Si nanomembrane (Si NM)-based bipolar-complementary metal-oxide-semiconductor (BiCMOS) thinfilm transistors (TFTs), including n-type MOSFET (NMOS), p-type MOSFET (PMOS), and NPN bipolar junction transistors (BJTs) with a single batch of microfabrication process
The fabrication process for flexible Si NM-based BiCMOS TFTs is shown in Fig. 1a and consists of three major steps: a multiple ion implantation step (Fig. 1a ii), a transfer-printing step (Fig. 1a v), and a microfabrication step (Fig. 1a vii)

Summary

Introduction

Complementary metal-oxide semiconductor (CMOS) transistors have clear advantages over their counterpart, bipolar transistors, such as lower power dissipation and higher packing density. BiCMOS technology, which is a combination of bipolar technology and CMOS technology, was developed to achieve complementary advantages from both technologies and offer lower power dissipation, and better gain and current driving capability on the same Si chip.[3, 4] As a result, BiCMOS technology has been widely used in logic circuits and mixed-signal systems[5,6,7,8] in electronics industry for the last two decades or so. The single-crystalline semiconductor nanomembranes (NMs) that were investigated over the last decade exhibit good flexibility for doping to fabricate n-type MOSFET (NMOS) and p-type MOSFET (PMOS) TFTs, and offer excellent mechanical durability and electronic properties.[18,19,20] it enables us to demonstrate high performance flexible CMOS TFTs such as flexible RF TFTs, high sensitivity light sensors, bio-medical devices, and environment-friendly devices.[12,13,14,15,16, 21,22,23,24] these demonstrations were very successful on their own, all of them have been fabricated using CMOS technology that is inadequate to handle high power signals or to satisfy more functionally advanced flexible electronics

Methods

Results

Conclusion