Abstract

The effect of different heat treatments on stoichiometry and residual gas pressure in ZnSe physical vapor transport system was investigated. The dependence of the amount and composition of the residual gas on various heat treatment procedures is reported. Heat treatment of ZnSe starting materials by baking under the condition of dynamic vacuum to adjust its stoichiometry was performed and the effectiveness of the treatment was confirmed by the measurements of the partial pressure of Se₂, P_Se2, in equilibrium with the heat treated samples. Optimum heat treatment procedures on the ZnSe starting material for the physical vapor transport process are discussed and verified experimentally.

Article Outline

1. Introduction

2. Experimental procedure

2.1. Residual gas

2.1.1. Sample preparation and treatments

2.1.2. Residual gas measurements

2.2. Partial pressure

2.2.1. Sample preparation and heat treatment

2.2.2. Partial pressure measurements

2.3. Crystal growth experiments

3. Results and discussion

3.1. Residual gas pressure and compositions

3.2. Partial pressure measurements

3.3. Crystal growth

4. Conclusions

Acknowledgements

References

(5K)
Fig. 1. Theoretically calculated mass flux of ZnSe as a function of the residual gas pressure for different partial pressure ratios at the source, (L), with the source temperature at 1080°C, T =20°C and transport length L=10 cm. The composition of the inert gas used in the calculation was 35% CO₂, 50% CO and 15% H₂. The solid dots on the left axis are the respective mass flux values assuming zero inert gas pressure.

(6K)
Fig. 2. The measured partial pressures of Se₂, P_Se2, for the optical cells ZnSe(O)-1, -2, -3 and -4, in equilibrium with ZnSe solid at different temperatures. The pressure ratio, , at the highest experimental temperature of each cell was labelled. The calculated P_se2 for the congruent sublimation condition is also given.

(112K)
Fig. 3. The ampoules after the crystal growth process. (a) Chunk source material, baked at 280°C under dynamic vacuum for 13 min. (b) Powdered source, annealed under H₂ atmosphere at 1015°C for 30 min then baked at 1045°C for 20 min.

Table 1. Source preprocess and sample treatment procedures for residual gas pressure measurements. Vendor I – Cleveland crystals, 59 purity; vendor II – Eagle–Picher high purity grade (<1K)

Table 2. Residual gas pressures and compositions in the processed ZnSe ampoules (<1K)

Table 3. Sample heat treatment procedures for the partial pressure measurements. Source sample: ground Eagle–Picher high-purity grade ZnSe (11K)

References

1. R.F. Brebrick and H.-C. Liu. High Temp. Mater. Sci. 35 (1996), p. 215. Abstract-INSPEC  

2. R.F. Brebrick and H.-C. Liu. J. Phase Equilibria 17 (1996), p. 495. Abstract-Compendex | Abstract-INSPEC  

3. R.C. Sharma and Y.A. Chang. J. Crystal Growth 88 (1988), p. 193. Abstract

4. Y.-G. Sha, C.-H. Su, W. Palosz, M.P. Volz, D.C. Gillies, F.R. Szofran, S.L. Lehoczky, H.-C. Liu and R.F. Brebrick. J. Crystal Growth 146 (1995), p. 42. Abstract | Abstract + References | PDF (518 K)

5. R.F. Brebrick. J. Electrochem. Soc. 116 (1969), p. 1274. Abstract-INSPEC  

6. P. Goldfinger and M. Jeunehomme. Trans. Faraday Soc. 59 (1963), p. 2851.

7. P.Z. Floegel. Anorg. Allg. Chem. 370 (1969), p. 16.

8. R.F. Brebrick. J. Electrochem. Soc. 118 (1971), p. 2014. Abstract-INSPEC  

9. M.M. Faktor, I. Garrett, Growth of Crystals from the Vapour, Chapman & Hall, London, 1974.

10. C.-H. Su. J. Crystal Growth 80 (1987), p. 333. Abstract

11. C.-H. Su, Y.-G. Sha, K. Mazuruk, S.L. Lehoczky, H.-C. Liu, R. Fang and R.F. Brebrick. J. Crystal Growth 166 (1996), p. 736. SummaryPlus | Full Text + Links | PDF (589 K)

12. J.H. Greenberg, V.N. Guskov, V.B. Lazarev and O.V. Shebershneva. J. Solid State Chem. 102 (1993), p. 382. Abstract

13. R. Fang and R.F. Brebrick. J. Phys. Chem. Solids 57 (1996), p. 443. Abstract | Abstract + References | PDF (846 K)

14. C.-H. Su, Y.-G. Sha, S.L. Lehoczky, H.-C. Liu, R. Fang and R.F. Brebrick. J. Crystal Growth 183 (1998), p. 519. SummaryPlus | Full Text + Links | PDF (360 K)

15. G.J. Russell and J. Woods. J. Crystal Growth 46 (1979), p. 323. Abstract

16. G. Schmidt and R. Gruehn. J. Crystal Growth 57 (1982), p. 585. Abstract

17. Y. Morimoto, T. Igarashi, H. Sugahara and S. Nasu. J. Non-Cryst. Solids 139 (1992), p. 35. Abstract-Compendex | Abstract-INSPEC  

18. W. Palosz and H. Wiedemeier. J. Crystal Growth 131 (1993), p. 193. Abstract

19. W. Palosz, F.R. Szofran and S.L. Lehoczky. J. Crystal Growth 142 (1994), p. 215. Abstract

20. R.F. Brebrick and A.J. Strauss. J. Phys. Chem. Solids 26 (1965), p. 989. Abstract

21. C.-H. Su, P.-K. Liao, T. Tung and R.F. Brebrick. High Temp. Sci. 14 (1981), p. 181.

22. R.F. Brebrick. J. Chem. Phys. 43 (1965), p. 3846.

23. Y. Huang and R.F. Brebrick. J. Electrochem. Soc. 135 (1988), p. 486. Abstract-Compendex | Abstract-INSPEC  

24. R.F. Brebrick and A.J. Strauss. J. Chem. Phys. 40 (1964), p. 3230.

25. R.F. Brebrick and A.J. Strauss. J. Chem. Phys. 41 (1964), p. 197.

26. Y. Huang and R.F. Brebrick. J. Electrochem. Soc. 135 (1988), p. 1547.

27. J.P. Schwartz, T. Tung and R.F. Brebrick. J. Electrochem. Soc. 128 (1981), p. 438. Abstract-Compendex  

28. T. Tung, L. Golonka and R.F. Brebrick. J. Electrochem. Soc. 128 (1981), p. 451.

29. C.-H. Su, P.-K. Liao and R.F. Brebrick. J. Electrochem. Soc. 132 (1985), p. 942. Abstract-INSPEC | Abstract-Compendex  

30. K.-T. Chen, Y.-G. Sha and R.F. Brebrick. J. Vac. Sci. Technol. A 8 (1990), p. 1086. Full Text via CrossRef

31. W. Palosz. J. Crystal Growth 173 (1997), p. 427. SummaryPlus | Full Text + Links | PDF (868 K)

32. C.-H. Su, S.L. Lehoczky and F.R. Szofran. J. Crystal Growth 101 (1990), p. 221. Abstract

33. C.-H. Su, M.P. Volz, D.C. Gillies, F.R. Szofran, S.L. Lehoczky, M. Dudley, G.D. Yao and W. Zhou. J. Crystal Growth 128 (1993), p. 627. Abstract-INSPEC | Abstract-Compendex  

34. C.-H. Su, Y.-G. Sha, M.P. Volz, D.C. Gillies, F.R. Szofran, S.L. Lehoczky, W. Zhou, M. Dudley, H.-C. Liu, R.F. Brebrick, AIAA paper 94-0564, 1994.

35. C.-H. Su, Proc. SPIE – The Int. Society for Optical Engineering, vol. 3123, 1997, p. 7.

36. W. Palosz, J. Crystal Growth, submitted.

^*Corresponding author. Fax: +1 205 544 8762.

¹Universities Space Research Association.

²Raytheon STX Corp.