| Type of Document |
Dissertation |
| Author |
Zhou, Xing
|
| URN |
etd-11212006-101726 |
| Title |
Charge Trapping Properties of Alternative High-k Dielectrics in MOS Devices |
| Degree |
PhD |
| Department |
Materials Science and Engineering |
| Advisory Committee |
| Advisor Name |
Title |
| Daniel M. Fleetwood |
Committee Chair |
| Bridget R. Rogers |
Committee Member |
| Robert A. Weller |
Committee Member |
| Ronald D. Schrimpf |
Committee Member |
| Sokrates T. Pantelides |
Committee Member |
|
| Keywords |
- hydrogen
- trap charge density
- alternative dielectrics
- long-term reliability
- microelectronic devices
|
| Date of Defense |
2006-10-12 |
| Availability |
unrestricted |
Abstract
High-k dielectrics are promising candidates to replace SiO2 in advanced integrated circuits in future space systems. Studies of the effects of ionizing radiation and bias-temperature stress (BTS) on high-k dielectrics were performed. Trapped charge densities are evaluated as functions of temperature and stress time. Prior radiation exposure enhances BTS-induced degradation in these devices. Worst-case responses in combined effects are positive (or zero) bias irradiation followed by NBTS for HfO2-based devices. Degradation due to oxide or interface trap-charge changes in magnitude with the bias polarity during switched-bias annealing either after irradiation or constant voltage stress (CVS). This demonstrates that metastable electron trapping (dominant during post-rad annealing) and hydrogen transport and reactions (dominant during post-CVS annealing) in the near-interfacial dielectric layers play significant roles in the defect formation process. Additional defect growth with time was observed as a result of additional charge injection through the gate stacks during the annealing process. These results provide insights into fundamental trapping properties of high-k dielectrics and can be used to help predict long-term reliability of these devices.
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| Files |
| Filename |
Size |
Approximate Download Time
(Hours:Minutes:Seconds)
|
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56K Modem |
ISDN (64 Kb) |
ISDN (128 Kb) |
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| |
XingZhou-PhD-dissertation.pdf |
1.55 Mb |
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