Smartkem, Inc. announced that it has entered into a joint development agreement with Shanghai Tianma Microelectronics Co. Ltd. to integrate Smartkem's Organic Thin-Film Transistor (OTFT) technology with Tianma's oxide transistors to develop OTFT-based microarray biochips. Devices made using the combination of complementary transistor polarities (CMOS) will include logic gates, both analog and digital, and these will be used to amplify and process signals generated by TFT-based sensor devices.

Whilst CMOS devices using oxide and OTFT have been trialled before with promising results published in scientific journals, this will be the first time that Smartkem's OTFTs will be combined with oxide transistors in a commercial setting. The high charge mobility organic transistors of Smartkem at short transistor channel lengths, which represents its ability to drive current, is intended to surpass the performance of previous test results of the OTFT/oxide combination. If successful, the company believes that the integration of OTFT on oxide will open the possibility of large area, high noise margin, low power logic devices for a range of sensor and internet of things (IOT) applications that do not require high frequency operation of CMOS silicon devices.

Oxide transistors are already scaled to Gen 8.5 substrates (2.25m x 2.5m) and Smartkem's solution processable OTFT is compatible with amorphous silicon (a-Si) process lines. a-Si processes currently run on Gen 10.5 substrates which are 2.94m x 3.37m in size. The overall production cost of the logic devices using organic-oxide CMOS is anticipated to be substantially lower than for silicon of the same size due to the low cost per area processes used for TFT fabrication.

This is due to the substrate size difference, the largest Gen10.5 substrate being 135X larger in area than a 12" wafer. The project involves collaborative work with Prof Xiaojun Guo's group at Shanghai Jiao Tong University (SJTU), which will be responsible for device architecture, process-to-design methodologies, and sensor integration. SmartKem and SJTU recently published a joint paper in Nature Communications on their work to integrate OTFT with III-V semiconductor micro-LED wafers for high brightness displays.