Abstract
Biosensors are commonly produced using a silicon-on-insulator (SOI) CMOS process and advanced lithography to define nanowires. In this paper, a simpler and cheaper junctionless three-mask process is investigated, which uses thin-film technology to avoid the use of SOI wafers, in situ doping to avoid the need for ion implantation and direct contact to a low-doped polysilicon film to eliminate the requirement for heavily doped source/drain contacts. Furthermore, TiN is used to contact the biosensor source/drain because it is a hard resilient material that allows the biosensor chip to be directly connected to a printed circuit board without wire bonding. pH sensing experiments, combined with device modeling, are used to investigate the effects of contact and series resistance on the biosensor performance, as this is a key issue when contacting directly to low-doped silicon. It is shown that in situ phosphorus doping concentrations in the range 4 × 1017-3 × 1019 cm-3 can be achieved using 0.1% PH3 flows between 4 and 20 sccm. Furthermore, TiN makes an ohmic contact to the polysilicon even at the bottom end of this doping range. Operation as a biosensor is demonstrated by the detection of C-reactive protein, an inflammatory biomarker for respiratory disease.
| Original language | English |
|---|---|
| Article number | 6803975 |
| Pages (from-to) | 2170-2176 |
| Number of pages | 7 |
| Journal | IEEE Transactions on Electron Devices |
| Volume | 61 |
| Issue number | 6 |
| DOIs | |
| Publication status | Published - Jan 1 2014 |
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All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering
Cite this
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Three-mask polysilicon thin-film transistor biosensor. / Sun, Kai; Zeimpekis, Ioannis; Lombardini, Marta; Ditshego, Nonofo M.Jack; Pearce, Stuart J.; Kiang, Kian S.; Thomas, Owain; De Planque, Maurits R.R.; Chong, Harold M.H.; Morgan, Hywel; Ashburn, Peter.
In: IEEE Transactions on Electron Devices, Vol. 61, No. 6, 6803975, 01.01.2014, p. 2170-2176.Research output: Contribution to journal › Article
TY - JOUR
T1 - Three-mask polysilicon thin-film transistor biosensor
AU - Sun, Kai
AU - Zeimpekis, Ioannis
AU - Lombardini, Marta
AU - Ditshego, Nonofo M.Jack
AU - Pearce, Stuart J.
AU - Kiang, Kian S.
AU - Thomas, Owain
AU - De Planque, Maurits R.R.
AU - Chong, Harold M.H.
AU - Morgan, Hywel
AU - Ashburn, Peter
PY - 2014/1/1
Y1 - 2014/1/1
N2 - Biosensors are commonly produced using a silicon-on-insulator (SOI) CMOS process and advanced lithography to define nanowires. In this paper, a simpler and cheaper junctionless three-mask process is investigated, which uses thin-film technology to avoid the use of SOI wafers, in situ doping to avoid the need for ion implantation and direct contact to a low-doped polysilicon film to eliminate the requirement for heavily doped source/drain contacts. Furthermore, TiN is used to contact the biosensor source/drain because it is a hard resilient material that allows the biosensor chip to be directly connected to a printed circuit board without wire bonding. pH sensing experiments, combined with device modeling, are used to investigate the effects of contact and series resistance on the biosensor performance, as this is a key issue when contacting directly to low-doped silicon. It is shown that in situ phosphorus doping concentrations in the range 4 × 1017-3 × 1019 cm-3 can be achieved using 0.1% PH3 flows between 4 and 20 sccm. Furthermore, TiN makes an ohmic contact to the polysilicon even at the bottom end of this doping range. Operation as a biosensor is demonstrated by the detection of C-reactive protein, an inflammatory biomarker for respiratory disease.
AB - Biosensors are commonly produced using a silicon-on-insulator (SOI) CMOS process and advanced lithography to define nanowires. In this paper, a simpler and cheaper junctionless three-mask process is investigated, which uses thin-film technology to avoid the use of SOI wafers, in situ doping to avoid the need for ion implantation and direct contact to a low-doped polysilicon film to eliminate the requirement for heavily doped source/drain contacts. Furthermore, TiN is used to contact the biosensor source/drain because it is a hard resilient material that allows the biosensor chip to be directly connected to a printed circuit board without wire bonding. pH sensing experiments, combined with device modeling, are used to investigate the effects of contact and series resistance on the biosensor performance, as this is a key issue when contacting directly to low-doped silicon. It is shown that in situ phosphorus doping concentrations in the range 4 × 1017-3 × 1019 cm-3 can be achieved using 0.1% PH3 flows between 4 and 20 sccm. Furthermore, TiN makes an ohmic contact to the polysilicon even at the bottom end of this doping range. Operation as a biosensor is demonstrated by the detection of C-reactive protein, an inflammatory biomarker for respiratory disease.
UR - http://www.scopus.com/inward/record.url?scp=84901367000&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84901367000&partnerID=8YFLogxK
U2 - 10.1109/TED.2014.2315669
DO - 10.1109/TED.2014.2315669
M3 - Article
AN - SCOPUS:84901367000
VL - 61
SP - 2170
EP - 2176
JO - IEEE Transactions on Electron Devices
JF - IEEE Transactions on Electron Devices
SN - 0018-9383
IS - 6
M1 - 6803975
ER -