REPORT DOCUMENTATION PAGE					Form Approved OMB No. 0704-0188
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1. AGENCY USE ONLY (Leave Blank)		2. REPORT DATE 31 Dec 1997	3. REPORT TYPE AND DATES COVERED Interim Progress 1 Jan 1997 - 31 Dec 1997
4. TITLE AND SUBTITLE Non-Cesiated Solid State Electron Emitters (Cold Cathodes) & Their Applications in Vacuum Microelectronics					5. FUNDING NUMBERS DAAH04-95-1-0157
6. AUTHORS Prof. Umesh K. Mishra Robert D. Underwood
7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Department of Electrical & Computer Engineering University of California, Santa Barbara Santa Barbara, CA 93106					8. PERFORMING ORGANIZATION REPORT NUMBER
9. SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES) U.S. Army Research Office P.O. Box 12211 Research Triangle Park, NC 27709-2211					10. SPONSORING / MONITORING AGENCY REPORT NUMBER 33799-PH
11. SUPPLEMENTARY NOTES The views, opinions and/or findings contained in this report are those of the author(s) and should not be construed as an official Department of the Army position, policy or decision, unless so designated by other documentation.
12a. DISTRIBUTION / AVAILABILITY STATEMENT Approved for public release; distribution unlimited.					12b. DISTRIBUTION CODE
13. ABSTRACT (Maximum 200 words) GaN pyramids have shown promise as field emission electron sources. The stable surface and high electron concentration of GaN are advantages over other materials. The goal of the past year’s research has been to fabricate field emission devices to determine the promise of GaN based field emitters to practical vacuum microelectronic devices. To increase yield and lower the operating voltage of our cathodes, we reduced the size of our emitter arrays, and developed a very robust integrated anode process. The anode is an air-bridge structure over the emitter tips. Initial measurements of a 10-tip array using this structure produced emission of 1.5 mA at 500 V with ~2 mm anode-cathode separation. The operating voltage is about half our previous best result with an external anode. Gated GaN field emitter arrays have also been fabricated. Large arrays showed shorting problems. An effort has been made to produce smaller arrays. We have successfully fabricated smaller arrays that are currently waiting for measurement. Finally, a method of using the piezoelectric effect of pseudomorphically strained layers to lower the surface work function has been studied by simulation and promises even lower operating voltages of InGaN/GaN field emitters.
14. SUBJECT TERMS GaN, field emitter array, vacuum microelectronics, integrated anode, piezoelectric effect						15. NUMBER OF PAGES 7
pseudomorphic growth, InGaN						16. PRICE CODE
17. SECURITY CLASSIFICATION OF REPORT UNCLASSIFIED	18. SECURITY CLASSIFICATION OF THIS PAGE UNCLASSIFIED			19. SECURITY CLASSIFICATION OF ABSTRACT UNCLASSIFIED		20. LIMITATION OF ABSTRACT UL
NSN 7540-01-280-5500						Standard Form 298 (Rev. 2-89) Prescribed by ANSI Std. Z39-1 298-102