The University of Texas System

Mir Mohammad Sadeghi

Deji Akinwande

Seyedeh Maryam Mortazavi Zanjani

Milo Holt

The integration of monolayer graphene with a semiconductor device for gas sensing applications involves obtaining a CMOS device that is prepared to receive monolayer graphene channels. After population of the monolayer graphene channels on the CMOS device, electrical contacts are formed at each end of the monolayer graphene channels with interconnect vias having sidewalls angled at less then 90&#xb0;. Additional metallization pads are added at the location of the monolayer graphene channels to improve planarity and reliability of the semiconductor processing involved.

Integration of monolayer graphene with a semiconductor device

The sensitivity of a graphene gas sensor to a gas analyte molecule may be significantly enhanced using molecular doping, which may be as effective as substitutional doping and more effective than electric-field doping. In particular, the room temperature sensitivity of NO-doped graphene to NHwas measured to be comparable to the sensitivity of graphene doped with substitutional boron atoms and superior to that of undoped graphene by an order of magnitude. The detection limit for NO-doped graphene gas sensors was estimated to be about 200 ppb, which may be improved with extended exposure to NO, compared to a detection limit of about 1.4 ppm for undoped graphene. While the stability analysis of NO-doped graphene sensors indicates that the doping method may not be completely stable, molecular doping is nevertheless a candidate technique for sensitivity improvement by enhancing the initial carrier concentration.

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Austin, TX, United States of America

Mir Mohammad Sadeghi