AD-A280 159 U.S. OFFICE OF NAVAL RESEARCH GRANT N00014-91-J-1629 R&T Code 413S001 John Pazik, Scientific Officer Technical Report #16 An Atomic-Resolution Study of Overlayer Formation and Interfacial Mixing in the Interaction of Phosphorus with Si(oo1) by Y. Wang, X. Chen, and R.J. Hamers Prepared for Publication in 1 ELECTE 94-16505 Physical Review B JUNQ31,s(U May 10, 1993 Department of Chemistry University of Wisconsin-Madison Madison, WI 53706 Reproduction in whole or in part is permitted for any purpose of the United States Government. This document has been approved for public release and sale: its distribution is unlimited. 20 07
* REPORT DOCUiMENTATION PAGE, ~,...; -, t :' -, ap. N.vw *i Wo' suiq t*e 'r0 ý ',.,, US O LY 10 vo W a k) 2,REPO RT 0. JI. REPO RT TYPE SE NL :~d1 5/27/94 jinterim 6/1/93-5/31/94 1, GE C Y I. GENY AN O OA TES CO VENEO0 4- Th'At~o4hM-Tehsoltiotn Study of Overlayer Formation and S. funoing NUMMES Interfacial MIxing in the Interaction of Phosphorus Grant with Si(0O1) NOOOI1-91-J- 1629 G. AUTHOR(S) R&T Code 413S001 Y. Wan g, X. Chen and R. J. Hamers 7. PERFORMING ORGANIZATION NAME(S) AND AOORESS(ESI 4. PERFORMING ORGANIZATION REPORT NUMBER Department of Chemistry University of Wisconsin-Madison 1101 University Avenue Madison, WI 53706-1396 *. SPONSORING i MONITORING AGENCY NAME(S) AND AOORESSCES) 10. SPONSONtdG' MONITORING AGENCY RPORI NUMISER Office of Naval Research, Chemistry 800 North Quincy Street 1 Arlington, VA 1-11., SUPPL.EMENTARY NOTES i~s. OISTRISLUTIOWAVAILASILITY STATEMENT 12b. DISTRIBUTION CODE Unlimited ~1 13. ABSTRACT (Aoezamum Zod words) Scanning Tunneling Microscopy,ST tunneling spectroscopy, and Auger electron spectroscopy have been used to study the formation of phosphorusterminated silicon(oo1) surfaces by the thermal decomposition of phosphine (PH3). The STM images show that surface phosphorus atoms readily displace Si from the substrate, dramatically changing the overall surface morphology through the formation of large numrbers of islands and an extremie roughening of step edges. The surfaces are terminated with P-P dimers, but also contain alrge numbers of line defects which act as a strain relief mechanism. SIM images are used to determine the symrmetry of these line defects and are compared with mrodel defect structures. Line defects in the phosphorus-terminated surface both nucleate islands and also constrain their growth in one dimension, such that the phosphorus-terminated surfaces contain large numbers of extreme~ly anisotropic islands and very rough step edges. At lower phosphorus coverage, the STM experiments are able to identify Si and P atoms individually, revealing the formation of large numbers of Si-P heterodimers and the simrultaneous disappearanc of the strain-induced line defects. Counting statistics are used to study the equilibrium between SizSi, Si-P, and P-P diiners, showing that the surface is a nearl\ random alloy with a sligt nn-statistical prefeano for fomation of the Si-P tetezodkiitr. 14. SUIjECT TERMS Is. NUMBER Of PAGES 43 116. "RIC COO( 117. SECURITY CLASSIFICATION I18. SECURITY CLASSiFICATIO g SECURITY CLASSIFICATION 2.LMiTATION OF AUSTR OF REPORT Of THIS5 PAGE Of ABSTRACT Unclassified j Unclassif ied7 Unclassified I.S% 7540)-O28O-550O StOda m io~ 98 zo -
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1.5 7-0.5 -I-, -= 0-0.5 0 5 10 15 20 25 30 35 Distance (A) L
a LMM z Si LNI NI "ai I I I I I I 1 60 80 100 120 140 160 Auger Electron Energy (ev) b 8.... 6 Clean Silicon E.E=0 85 ev O0-2 "P-terminated Si -2~ B 2eV -41. "-..-01. ' I' ' ''... ". gap 1-1... -1.5-1 -0.5 0 0.5 1 1.5 2 2.53 Sample Bias (V) -J
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