The wide band noise voltage (equivalent thermal noise voltage at the gate) of a submicron MOSFET, working in saturation, exhibits a minimum value at a certain drain current. This is supported by measurements and theoretical analysis based on a suitable thermal noise model. This macroscopic noise model attributes the thermal noise of the drain current to the superposition of two noise sources originating from two separate regions of the transistor's channel (a gradual channel approximation region and a saturation region). The existence of a minimum of the noise spectral density at an optimum drain current (I/sub opt/), is well proved by measurements and is contradictory to the predictions of the current simulation program with integrated circuit emphasis (SPICE) models. An empirical way for evaluating analytically I/sub opt/ is given. The fact of the existence of a noise minimum for a submicron MOSFET, brings a phenomenological equivalence to the bipolar transistor and GaAs MESFET when they are employed at the first stage of an amplifier.
[1]
H. Williams,et al.
Analytical and experimental studies of thermal noise in MOSFET's
,
1994
.
[2]
M. Fukuma,et al.
Effects of the velocity saturated region on MOSFET characteristics
,
1994
.
[3]
A. Birbas,et al.
Thermal noise modeling for short-channel MOSFETs
,
1996
.
[4]
R. Jindal.
Hot-electron effects on channel thermal noise in fine-line NMOS field-effect transistors
,
1986,
IEEE Transactions on Electron Devices.
[5]
C. F. Krumm,et al.
Noise performance of gallium arsenide field-effect transistors
,
1976
.
[6]
A.A. Abidi,et al.
High-frequency noise measurements on FET's with small dimensions
,
1986,
IEEE Transactions on Electron Devices.
[7]
Robert G. Meyer,et al.
An engineering model for short-channel MOS devices
,
1988
.