Integrated circuit with nanowire ChemFET-sensors, sensing apparatus, measuring method and manufacturing method
Integrated circuit ( 100 ) comprising a semiconductor substrate ( 110 ); an insulating layer ( 120 ) over said substrate; an first transistor ( 140 ) on said insulating layer, said first transistor comprising an exposed channel region ( 146 ) in between a source region ( 142 a, 142 b ) and a drain region ( 144 ); and a voltage waveform generator ( 150 ) conductively coupled to the semiconductor substrate for providing the first transistor with a bias voltage during a signal acquisition period, wherein the voltage waveform generator is arranged to generate an alternating bias voltage waveform ( 300 ) comprising a periodically increasing amplitude. A sensing apparatus including such an integrated circuit and a sensing method using such an integrated circuit are also disclosed.
1. An integrated sensor circuit comprising:
a semiconductor substrate;
an insulating layer over said semiconductor substrate;
a first transistor on said insulating layer, said first transistor comprising an exposed channel region in between a source region and a drain region and a sensitive gate in said exposed channel region, the exposed channel region being arranged for sensing of an analyte; and
a voltage waveform generator conductively coupled to the semiconductor substrate for providing the first transistor with a bias voltage during a sensing signal acquisition period, wherein the voltage waveform generator is programmed to provide a bias voltage waveform comprising a plurality of alternating positive and negative voltage pulses, wherein only one of the positive voltage pulses and negative voltage pulses exhibits a periodically increasing amplitude and the other one of the positive voltage pulses and the negative voltage pulses remains constant.
2. The integrated sensor circuit of claim 1 , further comprising a signal processor conductively coupled to the first transistor and wherein the first transistor is arranged to derive a measurement of the analyte from a signal acquired during said sensing signal acquisition period.
3. The integrated sensor circuit of claim 1 , wherein the bias voltage waveform has a time-averaged zero potential, which preferably alternates around a zero value.
4. The integrated sensor circuit of claim 1 , wherein the exposed channel region is selected from a group consisting of: a nanowire and a nanotube.
5. The integrated sensor circuit of claim 4 , wherein the nanowire comprises a silicon nanowire.
6. The integrated sensor circuit of claim 4 , wherein the nanotube comprises a carbon nanotube.
7. The integrated sensor circuit of claim 1 , wherein the channel region is covered by an oxide layer.
8. The integrated sensor circuit of claim 1 , wherein the first transistor is part of a plurality of first transistors.
9. A sensing apparatus comprising: a sample compartment; and an integrated sensor circuit comprising: a semiconductor substrate; an insulating layer over said semiconductor substrate; a first transistor on said insulating layer, said first transistor comprising an exposed channel region in between a source region and a drain region and a sensitive gate in said exposed channel region, the exposed channel region being arranged for sensing of an analyte; and a voltage waveform generator conductively coupled to the semiconductor substrate for providing the first transistor with a bias voltage during a sensing signal acquisition period, wherein the voltage waveform generator is programmed to provide a bias voltage waveform comprising a plurality of alternating positive and negative voltage pulses, wherein only one of the positive voltage pulses and negative voltage pulses exhibits a periodically increasing amplitude and the other one of the positive voltage pulses and the negative voltage pulses remains constant, wherein the first transistor is exposed to said sample compartment.
10. The sensing apparatus of claim 9 , wherein said sample compartment comprises a flow channel.
11. A method of measuring an analyte of interest in a medium, the method comprising: providing an integrated sensor circuit comprising: a semiconductor substrate; an insulating layer over said semiconductor substrate; a first transistor on said insulating layer, said first transistor comprising an exposed channel region in between a source region and a drain region and a sensitive gate in said exposed channel region, the exposed channel region being arranged for sensing of an analyte; and a voltage waveform generator conductively coupled to the semiconductor substrate for providing the first transistor with a bias voltage during a sensing signal acquisition period, wherein the voltage waveform generator is programmed to provide a bias voltage waveform comprising a plurality of alternating positive and negative voltage pulses, wherein only one of the positive voltage pulses and negative voltage pulses exhibits a periodically increasing amplitude and the other one of the positive voltage pulses and the negative voltage pulses remains constant; exposing the first transistor to a medium potentially including an analyte to be sensed with the first transistor; and deriving an analyte measurement from a signal acquired during said sensing signal acquisition period.
12. The method of claim 11 , wherein the bias voltage waveform has a time-averaged zero potential.
13. The method of claim 11 , wherein the bias voltage waveform alternates around a zero value.