MacEtch method makes tall, narrow finFETs
Exploring next-generation 2D materials and transistor designs
Illinois researchers led by Professor Xilung Li( right) have developed a method to etch tall, thin transistors for high performance with less error. Other team members include graduate student Yi Song( center) and ECE Emeritus Professor Ilesanmi Adesida( left).
MacEtch method makes tall, narrow finFETs
Smaller and faster has been the trend for electronic devices since the inception of the computer chip, but flat transistors have gotten about as small as physically possible. For researchers pushing for even faster speeds and higher performance, building up is one way to go. ECE Professor Xiuling Li has developed a way to etch very tall, narrow finFETs, a type of transistor that forms a tall semiconductor“ fin” for the current to travel over. Her group’ s unique etching technique, known as metal-assisted chemical etching( MacEtch), addresses many problems in trying to create 3-D devices, typically done now by stacking layers or carving out structures from a thicker semiconductor wafer. Li’ s smooth finFETS, which are made of indium phosphide, have aspect ratios that are impossible for other existing fabrication methods to reach. In addition to transistors, the MacEtch technique could also apply to many other types of devices or applications that use 3-D semiconductor structures, such as computing memory, batteries, solar cells and LEDs, as well as scaffolds for biomaterials.
Source: IEEE Electron Device Letters,“ Ultra-high aspect ratio InP junctionless finFETs by a novel wet etching method,” volume 37, issue 8, August 2016.
Exploring next-generation 2D materials and transistor designs
Although it has driven innovation in the semiconductor industry for 50 years, silicon CMOS technology is reaching its limits as transistor feature sizes( 14 nanometers and shrinking) may soon become too small to manufacture efficiently and cost effectively. ECE Assistant Professor Wenjuan Zhu and her students are exploring next-generation two-dimensional( 2D) materials and transistor designs as an alternative to silicon CMOS. In 2016, her group demonstrated heterojunction transistors made from germanium selenium( GeSe) and molybdenum disulfide( MoS 2
). These 2D transistors are essential components of tunnel field-effect transistors( TFETs) and are ideally suited for low power applications such as mobile phones and implanted medical devices. Her group also systematically investigated the spatial / temporal photocurrent and electronic transport of monolayer MoS 2 grown by chemical vapor deposition( CVD), which provides a viable path for nextgeneration flexible electronic and optoelectronic circuits. Source: Applied Physics Letters,“ Spatial / temporal photocurrent and electronic transport in monolayer molybdenum disulfide grown by chemical vapor deposition,” volume 108, issue 8, February 2016.
ECE Assistant Professor Wenjuan Zhu and her students demonstrated novel 2D transistors that could someday be used in mobile phones and implanted medical devices.
MNTL | 8 | University of Illinois at Urbana-Champaign