Skip to main content Accessibility help

(A)thermal migration of Ge during junction formation in s-Si layers grown on thin SiGebuffer layers

  • W. Vandervorst (a1) (a2), B.J. Pawlak (a3), T. Janssens (a4), B. Brijs (a4), R. Delhougne (a4), M. Caymax (a4) and R. Loo (a4)...


Solid phase epitaxial regrowth (SPER) has been proven to be highly advantageous for ultra shallow junction formation in advanced technologies. Application of SPER to strained Si/SiGe structures raises the concern that the Ge may out diffuse during the implantation and/or anneal steps and thus reduce the strain in the top silicon layer.

In the present studies we expose 8-30 nm strained silicon layers grown on thin relaxed SiGe-buffers, to implant conditions and anneal cycles, characteristic for formation of the junctions by solid phase epitaxial regrowth and conventional spike activation. The resulting Geredistribution is measured using SIMS. Based on the outdiffused Ge-profiles the Ge-diffusion coefficient has been determined in the temperature range of 800-1100C from which an activation energy of ∼ 3.6 eV can be deduced. Up to 1050 C, 10 min, even a 30 nm strained film remains highly stable and shows only very moderate outdiffusion.

We also have observed a far more efficient, athermal Ge-redistribution process linked to the implantation step itself. This was studied by analysing the Ge-redistribution following an Asimplant (2-15 keV, 5 1014 – 3 1015 at/cm2). It is shown that the energy of the implant species (or more specifically the position of the damage distribution function relative to the Ge-edge) plays a determining factor with respect to the Ge-migration. For implants whereby the damage distribution overlaps with the Ge-edge, a very efficient transport of the Ge is observed, even prior to any anneal cycle. The migration is entirely correlated with the collision cascade and the resulting (forward!) Ge-recoil distribution. The scaling with dose for a given energy links the observed Ge-profile with a broadening mechanism related to the number of atom displacements induced in the sample within the vicinity of the Si-SiGe-transition.



Hide All
1. Loo, R., Delhougne, R., Meunier-Beillard, P., Caymax, M., Verheyen, P., Eneman, G., Wolf, De, Janssens, T., Benedetti, A., Meyer, K. De, Vandervorst, W., and Heyns, M., these proceedings
2. Sugii, N., J. Appl. Phys 89, (2001), 6459
3. Crank, J., Mathematics of diffusion (Oxford University Press, 1956)
4. LeGoues, F.K., Meyerson, B.S. and Morar, J.F., Phys. Rev. lett 66,(1991), 2903
5. Ogino, M., Oana, Y. and Watanabe, M., Phys. Status Solidi A 72,(1982), 535
6. Dorner, P., Gust, W., Predel, B., Roll, U., Lodding, A. and Odelius, H., Philos. Amg. A49, (1984), 557
7. Prokes, S.M., Glembocki, O.J. and Godbey, D.J., Appl. Phys. Lett 60, (1992), 1087
8. Hettich, G., Mehrer, H. and Maier, K., Int. Conf on Defect and Radiation Effects in Semicond., Nice, France (1978).
9. Zangenberg, N.R., Hansen, J. Lundsgaard, Fage-Pedersen, J. and Larsen, A. Nylandsted, Phys. Rev. Lett. 87, (2001),125901
10. Cowern, N., Zalm, P.C., Sluis, P. van der, Graventsteijn, D.J. and Boer, W.B. de, Phys. Rev.Lett 72, (1994), 2585
11. Pawlak, B.J., Vandervorst, W., Lindsay, R., Wolf, I. de, Roozeboom, F., Delhougne, R., Benedetti, A., Loo, R., Caymax, M., Maex, K. these proceedings
12. Littmark, U., Nuclear Instruments & Methods in Physics Research, Section B vol.B7–8, (1985), 684–93, March 1985

(A)thermal migration of Ge during junction formation in s-Si layers grown on thin SiGebuffer layers

  • W. Vandervorst (a1) (a2), B.J. Pawlak (a3), T. Janssens (a4), B. Brijs (a4), R. Delhougne (a4), M. Caymax (a4) and R. Loo (a4)...


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed