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Tem Studies of Polysilicon Emitter Bipolar Materials & Devices: Increased Interfacial Oxide Break-Up and Polysilicon Regrowth and Decreased Emitter Resistance by Fluorine Implantation

Published online by Cambridge University Press:  10 February 2011

C. D. Marsh
Affiliation:
Dept of Materials, University of Oxford, Oxford OXI 3PH, UK.
N. E. Moiseiwitsch
Affiliation:
Dept of Electronics & Computer Science, University of Southampton, Southampton, UK.
J. Schiz
Affiliation:
Dept of Electronics & Computer Science, University of Southampton, Southampton, UK.
G. R. Booker
Affiliation:
Dept of Materials, University of Oxford, Oxford OXI 3PH, UK.
P. Ashburn
Affiliation:
Dept of Electronics & Computer Science, University of Southampton, Southampton, UK.
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Abstract

The role of fluorine (F) in the break-up of the native oxide and the regrowth of As doped poly-Si layers on unpatterned Si wafers and on patterned regions of Si device wafers at temperatures of 900°C to 1000°C are investigated by TEM and by the fabrication of npn poly-Si emitter bipolar devices. Results for unpatterned wafers with F show i) a 950°C dopant drive-in anneal causes oxide break-up and regrowth after a time suitable for the fabrication of devices, ii) a pre-anneal, before the As implant, further enhances the break-up and regrowth and iii) there is an optimum F dose of 5×1015/cm2. Based on these results poly-Si emitter bipolar devices were fabricated using F=5×1015/cm2, a pre-anneal and a 900°C As drive-in anneal. The results establish quantitatively the relationship between the interface structures and the specific emitter resistance, i.e. with no F there is no break-up or regrowth and the emitter resistance is high (114Ωμm2) while with F there is break-up and regrowth and the emitter resistance is low (17Ωμm2).

Type
Research Article
Copyright
Copyright © Materials Research Society 1998

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References

1. Williams, J. D. and Ashburn, P., J. Appl. Phys. 72, 3169 (1992).10.1063/1.351480Google Scholar
2. Wu, S. L., Lee, L. C., Lei, T. F., Chen, C. F., Chen, L., Ho, K. and Ling, Y., IEEE Elec. Dev. Lett. 15, 120 (1994).Google Scholar
3. Marsh, C. D., Moiseiwitsch, N. E, Booker, G. R. and Ashburn, P., Inst. Phys. Conf. Ser. 146, 457 (1995).Google Scholar
4. Moiseiwitsch, N. E., Marsh, C. D., Ashburn, P. and Booker, G. R., Appl. Phys. Lett. 66, 1918 (1995).10.1063/1.113276Google Scholar
5. Marsh, C. D., Moiseiwitsch, N. E, Booker, G. R. and Ashburn, P., Inst. Phys. Conf. Ser. 157, 411 (1997).Google Scholar
6. Schiz, J., Moiseiwitsch, N. E., Marsh, C. D., Ashburn, P. and Booker, G. R., Proc. ESSDERC 26, 461 (1996).Google Scholar