Schematic drawing showing the use of alternating proton :~m- plant masks (wire versus. SiOz) and the resultant electroop.ica1 graphs for two neighboring lasers ...
IEEE TRANSAf."TIONS ON ELECTRON DEVICES, ED-31, VOL.
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NO. 1 2 , DECEMBER 1984
state-of-the-artwafers(suchasthosegrown by MOCVD) where longer wires result in increased stripe variation due to excessivewire movement during implant and increasedirregular gaps occurring between the wafer surface and wire mask. TheSiOz maskcanbeapplied to wafers withvarioustypes of surfaces(e.g.,naturalor native-grownoxides,metallized, etc). Finally, if an error occurs prior to implant, an incorrect SiOz mask can be removed and the masking procedure simply repeated with no deleterious effects to the wafer.
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ACKNOWLEDGMENT The authors gratefully acknowledge the technical assistance of J. LopataforSiOz film depositions, D. J. Werder for M. Bogdanowicz for laseraging data. plasma etching, and C. R. B. Lawry is thanked for the deposition of the metal films used for the plasma etch masks. The LPE (A1,Ga)As wafers were grown, and kindly provided, by D. L. Van Haren.
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REFERENCES R. W. Dixon, BellSyst. Tech. J.,vol. 59, p. 669, 1980. I. C. Dyment, L. A. D'Asaro, J. C. North, B. I. Miller, and J . E. Ripper, Proc. IEEE, vol. 60, p. 726, 1972. G. Smith, IEEE J. QuantumElectron., vol. QE-17, p. 750, 1981. 3. F. Gibbons, W. S. Johnson,and S. W. Mybroie. Bojected Range Statistics of Semiconductors and Related Maternis, 2nd ed. Stroudsburg, PA: Dowden, Hutchinson, and Ross, Inc., 1975. H. H. AndersonandJ. F. Ziegler, HydrogenStoppingPowers and Ranges in A11 Elements. New York: Pergamon Press, 1977. V. M. Donnelly, D. L. Flamm, D. J. Werder,and W. C. DautremontSmith,J. Appl. Phys.,vol. 55, p. 242,1984. W. C. Dautremont-Smith and J. Lopata, J. VUC. Sci.Technol., vol. B1, p. 943,1983. R.H. Bruce and B. Geleront, Electrochem.SOC.Extended Abstracts, vol. 80-1, p. 307, 1980. R. H. Bruce, D. L. Flamm, V. M. Donnelly,and B. S. Duncan, Electrochem. SOC. ExtendedAbstracts, vol. 81-2, p. 631, 1981.
J. C. Dymentand
Fig. 3. Schematic drawing showing the use of alternating proton :~mplantmasks(wireversus SiOz)andtheresultantelectroop.ica1 graphs for two neighboring lasers.
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1 / 5 8 f 4 ) 2 8 f 0 5 ) 1 7 2 3 f 0 0 3 ) 2 6 i 3 1 0 3 8 f 71
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5 9 - 6 2 ~ 6 4 f 4 [ 3 1 ? 0 4 ~ 1 7 5 0 ~ 0 0 6 ~ 3 1 f 6 ~ 0 . 3 1110 f847tOZ
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The accelerated aging characteristics of each group ofdevices A minimum of ten laser!:of isalso summarizedinTableI. each masking structure was tested for reliability for each of two wafers, The lasers tested did not have mirror facet c w t ings nor were the wafers prescreenedforpotentially gcmd reliability.Thereforemoderatereliabilityforeach group1of lasers was obtained. After 800-1000 h of aging both groups, however,similar devicecharacteristics(withinexpected(listributions)indicatenoparticularinjuriouseffectsare Inparted when using the SiOz proton mask. CONCLUSION A new proton-bombardment masking technique is repor' c:d for stripe-geometry (A1,Ga)As lasers in which the mask clmsists of thick (2.5 pm) SiOz stripes which are formed by anislotropic plasmaetching.Linewidths can becontrolledwith
