Tu-B3.2
Tu-B3.2
CryoHEMTs for low-temperature, low-power and low-frequency readout
electronics: performance and applications
Y Jin, Q Dong, L Couraud, A Cavanna, U Gennser, F Pierre and C Ulysse
CNRS/LPN, Université Paris-Saclay, Marcoussis, France
Based on a long-term investigation of material growth and fabrication procedure, the
cryogHEMTs (Cryogenic High Electrons Mobility Transistors) made at the CNRS/LPN are
now in the process to fill the gap of the FET (Filed-Effet Transistor) for high impedance, lowpower and low-frequency deep cryogenic readout electronics. Different input capacitance
cryoHEMTs have been fabricated and characterized, and ultra-low noise voltage and noise
current have been obtained. As an example, at 4.2 K and with a large gate capacitance, the
noise voltage can decrease from 6 nV/Hz1/2 at 1 Hz to 0.32 nV/Hz1/2 at 1 kHz (see Fig.1, the
noise-voltage of the cryoHEMT at 4.2 K, compared to Si JFET at 300 K); the noise current
varies from 20 aA/Hz1/2 at 1 Hz to 0.5 fA/Hz1/2 at 1 kHz [1]. This transistor has been tested in
making a cryogenic readout circuit at UC Berkeley for a dark matter search experiment; the
detection threshold of 133 electrons by conventional readout electronics can be expected to be
reduced to only 35 electrons [2]! As another example, cryoHEMTs with a gate capacitance of
3.5 pF show a noise voltage of about 0.2 nV/Hz1/2 and a noise current of about 2 fA/Hz1/2 at 1
MHz and 4.2 K (see Fig.2, noise voltage and noise current spectra). These cryoHEMTs have
been used to build cryogenic preamplifiers with which it has been possible to realize new
observations in mesoscopic physics [3,4]. Details in device investigation, physical
understanding, comparison with conventional readout electronics and other applications will
be presented.
4
Input noise voltage
Input noise current
10
-8
10
-15
8
6
4
10
2
10
-16
-9
8
6
10
-17
Input noise current (A/Hz½)
Input noise voltage (V/Hz½)
2
4
2
0
10
10
1
10
2
3
10
4
10
10
5
6
10
Frequency (Hz)
Fig.1 Input noise voltage of the
cryoHEMT with the gate capacitance of 92
pF and a power consumption of 0.1 mW at
4.2 K, compared to Si JFETs at 300 K.
Fig.2 CryoHEMT with 3.5 pF input
capacitance, input noise spectra up to 1
MHz with a power supply 0.1 mW and at
4.2 K.
References
[1] Q. Dong, et al., Appl. Phys. Lett. 105, 13504 (2014).
[2] A. Phipps, et al., J Low Temp Phys (2016) DOI 10.1007/s10909-016-1475-2
[3] S. Jezouin, et al., Science 342, 601 (2013)
[4] V. Freulon, et al., Nature Commun. 6, 20 (2015).