Development of a standard cell library and ASPEC design flow for Organic Thin Film Transistor technology

Abstract

Application Specific Printed Electronics Circuit (ASPEC), a circuit designed and customized for a special application rather than intended for general-purpose use, is the equivalent term for ASIC but for printed electronics. In this paper, we extend the printed electronics to ASPEC design by developing a standard cell library for CPI (center for Process Innovation) technology which substrate is flexible PEN(50 micron thickness), laminated to glass using the PDMS bounding process. Standard cells topology allows full automation of the layout design process using automated place and route tools. In addition, Standard cells significantly help speeding the circuit development time as the blocks can be synthesized from high level descriptions (Verflog, VHDL) using the library. The cell library is generated for two different types of Top-gate bottom contact Organic Thin Film Transistors (OTFTs): l)Inter-digitated OTFT, 2)Corbino OTFT. The pseudo ratioed pMOS lodic is used for the circuitry since only p-channel transistors are available. The developed library consists of 7 gates: 5 combinational gates (Inverter, NAND2, NAND3, NAND4, and XOR2) and 2 sequential gates (D flip flop and enable D flip flop) and a FEED cell. Glade layout editor and MaskEngineer 4.8.4 and AIMSpice simulator have been used to design the cells layout and simulate the cell circuits. Automatic extraction of electrical interconnections from layout has been done in order to enable layout versus schematic (LVS). Finally, Tic-Tac-Toe game using combinational circuit has been designed, fabricated and will be characterized to demonstrate the standard cell library.