1. Ischia, 21-23 giugno 2006Riunione Annuale GE 2006 Gate-oxide breakdown under RF stress: experiments, analysis, and effect on circuit operation 1 Università di Pavia 2 Università di Modena e Reggio Emilia D. Sanzogni 1, L. Larcher 2, R. Brama 2, A. Mazzanti 2, F. Svelto 1

2. Ischia, 21-23 giugno 2006Riunione Annuale GE 2006 Introduction Limits of literature papers: BD and Hot Carrier (HC) effects on devices and circuits (Low Noise Amplifier and Mixer) studied only after DC stresses. Need for oxide lifetime investigation and new BD limits at RF.

3. Ischia, 21-23 giugno 2006Riunione Annuale GE 2006 High Efficiency Power Amplifiers V G =1.28 V DD +V T V in =±V DD V DG1,MAX =V DG2,MAX =2.28V DD -V T The peak V DS voltage is divided between the two devices

4. Ischia, 21-23 giugno 2006Riunione Annuale GE 2006 Experimental Results: P OUT Voltage accelerated stress V dd = 4, 4.5 and 5V. freq = 1.8GHz

5. Ischia, 21-23 giugno 2006Riunione Annuale GE 2006 Broken MOS fingers mod- eled through resistors [1] R GG accounts for doping diffusion through broken oxide; R SS & R DD account for broken n-well to S/D. Equivalent Model V DD [V]V DG,MAX [V] R GG [ ]R DD [ ]R SS [ ] 410.4150015 4.511.370015 512.150015 [1] Y.-S. Yeoh, et al. Proc. IEEE 33 rd IRPS, pp. 149-155, 1995.

6. Ischia, 21-23 giugno 2006Riunione Annuale GE 2006 Higher voltage peaks can be tolerated @ RF. Estimated Time to Breakdown

7. Ischia, 21-23 giugno 2006Riunione Annuale GE 2006 Conclusions Voltage DC breakdown limits are too conservative when the stress is at RF Oxide degradation due to RF stress is explained and modeled by considering the RMS value of the oxide field as the stress triggering parameter Higher voltage peaks can be tolerated leading to new design perspectives in CMOS RF circuits BD effects on class-E PA operation could be tolerated using proper circuit topologies