1. Radiation Tolerance of a 0.18 mm CMOS Process
M. Manghisonic,d, L. Rattia,c, V. Reb,c, V. Spezialia,c
a Università di Pavia, Dipartimento di Elettronica, Pavia, Italy
b Università di Bergamo, Dipartimento di Ingegneria, Dalmine, Italy
c INFN, Sezione di Pavia, Pavia 27100, Italy
d Studio di Microelettronica, STMicroelectronics, Pavia, Italy
7th International Conference on
Advanced Technology and Particle Physics
Villa Olmo, October 2001

2. Outline Submicron CMOS technologies and their radiation hardness
V.Re, "Radiation Tolerance of a 0.18 mm CMOS Process"
Outline
Submicron CMOS technologies and their radiation hardness
Static, signal and noise characterization of irradiated NMOS and PMOS devices belonging to a 0.18 mm process
Comparison with NMOS and PMOS transistors belonging to a 0.35 mm technology
7th International Conference on Advanced Technology and Particle Physics, Villa Olmo, October 2001

3. Submicron CMOS technologies
V.Re, "Radiation Tolerance of a 0.18 mm CMOS Process"
Submicron CMOS technologies
High density mixed-signal front-end systems for high granularity detectors (microstrip, pixel)
Reduced thickness of the gate oxide: mm: tOX=7.2 nm mm: tOX=5.5 nm mm: tOX=4 nm
Improved radiation hardness
Present focus: 0.25 mm CMOS
Characterization of the following CMOS generation
(0.18 mm)
7th International Conference on Advanced Technology and Particle Physics, Villa Olmo, October 2001

4. Test and irradiation conditions
V.Re, "Radiation Tolerance of a 0.18 mm CMOS Process"
Test and irradiation conditions
0.18 mm CMOS process by ST Microelectronics
Standard open structure layout (no special radiation hard technique)
Irradiation up to 100 kGy (10 Mrad) with a 60Co source
Devices biased during irradiation at normal operating conditions
7th International Conference on Advanced Technology and Particle Physics, Villa Olmo, October 2001

5. Static characterization: ID-VGS
V.Re, "Radiation Tolerance of a 0.18 mm CMOS Process"
Static characterization: ID-VGS
7th International Conference on Advanced Technology and Particle Physics, Villa Olmo, October 2001

6. V.Re, "Radiation Tolerance of a 0.18 mm CMOS Process"
Threshold voltage
PMOS: decrease of less 10 mV in Vth after a 100 kGy dose
NMOS: Vth drop of about
10 mV after a 100 kGy dose
7th International Conference on Advanced Technology and Particle Physics, Villa Olmo, October 2001

7. Signal parameters: transconductance
V.Re, "Radiation Tolerance of a 0.18 mm CMOS Process"
Signal parameters: transconductance
7th International Conference on Advanced Technology and Particle Physics, Villa Olmo, October 2001

8. Noise characterization: noise voltage spectra
V.Re, "Radiation Tolerance of a 0.18 mm CMOS Process"
Noise characterization: noise voltage spectra
Small changes over the entire frequency interval after irradiation
Model of the noise power spectral density 4 k T a A 2 + S ( f ) = f n g f m
7th International Conference on Advanced Technology and Particle Physics, Villa Olmo, October 2001

9. Noise characterization: white noise
V.Re, "Radiation Tolerance of a 0.18 mm CMOS Process"
Noise characterization: white noise
Very low radiation sensitivity of the white noise
The increase in white noise is never larger than 15% (it is very small in PMOS devices)
7th International Conference on Advanced Technology and Particle Physics, Villa Olmo, October 2001

10. Noise characterization: 1/f noise
V.Re, "Radiation Tolerance of a 0.18 mm CMOS Process"
Noise characterization: 1/f noise
Although to a limited extent, 1/f noise is affected by irradiation
The Af parameter increases less than a factor of 2
7th International Conference on Advanced Technology and Particle Physics, Villa Olmo, October 2001

11. 0.18 mm process vs 0.35 mm process Threshold Voltage

12. 0.18 mm process vs 0.35 mm process

13. 0.18 mm process vs 0.35 mm process

14. 0.18 mm process vs 0.35 mm process Noise voltage spectrum

15. V.Re, "Radiation Tolerance of a 0.18 mm CMOS Process"
Conclusions
Static and noise characterization under irradiation of submicron N and P-channel MOSFETs has been performed
The investigated devices exhibited a good radiation tolerance up to 100 kGy absorbed dose of ionizing radiation
The intrinsic radiation hardness of submicron CMOS processes has been confirmed
7th International Conference on Advanced Technology and Particle Physics, Villa Olmo, October 2001