SBIR-STTR Award

The work outlined in this proposal is directed toward the development of materials and fabrication processes for organic-based complementary circuits. New and improved n-channel (electron transporting) semiconductors will be synthesized and characterized at Northwestern University. These materials will possess a mobility of about 1 cm2/V-s and will be combined with p-channel FET materials such as pentacene (mobility ~ 1 cm2/V-s) to realize an organic complementary circuit technology. The speed of complementary circuits with materials possessing a mobility of 1 cm2/V-s will be equivalent to p-channel FET circuits with a mobility of 10 cm2/V-s, underscoring the importance of developing complementary technology. The fabrication of the transistors will be performed by OrganicID and will include detailed investigations of the best insulator-semiconductor combinations for both top-gate and bottom gate devices. The channel lengths of these devices will extend to below 5 micrometers. The analysis and improvement of injecting contacts will be subcontracted to the University of Texas. The development of a practical organic complementary technology is vital to the business goals of OrganicID which is engaged in building low-cost radio frequency identification tags and other circuitry. Complementary circuits will result in lower power requirements, greater range, and faster speed

Objective The objective of this project is to develop an organic solution-based CMOS process capable of producing printed RFID tags. Key to this objective is to optimize the n-type semiconductor and dielectric materials developed in Phase I, and to integrate these materials into a complete process line. The Approach CMOS utilizes p-type and n-type transistors to significantly reduce static power dissipation while increasing the performance of circuitry by an order of magnitude greater than the p-type (or n-type) counterpart alone. We propose to develop and implement an end-to-end process line which is capable of fabricating commercial product at target costs. This will be a collaborative effort wherein Northwestern University optimizes the n-type material and dielectric sets that have been explored in Phase I, the University of Texas enhances the performance and manufacturability of n-type transistors based on the device physics elucidated in Phase I, and OrganicID integrates those materials to form a complete CMOS process. A number of fabricated design structures are proposed as a demonstration vehicle, including a simplified RFID tag operating at 13.56MHz. The approach to the enabling n-type materials will be to optimize film growth processes for structures having electron-withdrawing groups and other substituents to drastically lower highest occupied molecular orbital energies (stabilizing injected electrons) and planar, extended electronic conjugation pathways to optimize close intermolecular packing and charge mobility. Dielectric materials will be optimized for low leakage, high dielectric breakdown strength, high capacitance, good environmental and mechanical stability, compatibility with both n- and p-type semiconductors, ease of uniform film growth, and compatibility with a variety of organic transistor electrodes and electrode configurations.

Keywords:
Organic Electronics, Printable Electronics, N-Type Organic Material, Disposable Electronics,