Vapor-Phase Stoichiometry and Heat Treatment of CdTe Starting Material for Physical Vapor Transport

10 Pages·1998·0.5 MB·English

by  Su, Ching-Hua

Reprinted from
CRYSTAL
JOURNALOF
GROWTH
Journal of Crystal Growth 183 (1998) 519 524
Vapor-phase stoichiometry and heat treatment
of CdTe starting material for physical vapor transport
Ching-Hua Su a'*, Yi-Gao Sha a' 1, S.L. Lehoczky a, Hao-Chieh Liu b, Rei Fang b,
R.F. Brebrick b
"Space Sciences Laboratory, NASA(cid:0)Marshall Space Flight Center. Huntsville, AL 35812, USA
Materials" Science and Metallurgy Program, Marquette University, Milwaukee. WI 53233. USA
Received 19April 1997; accepted 18 August 1997
ELSEVIER
Journal of Crystal Growth
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GROWTH
ELSEVIER Journal of Crystal Growth 183(1998) 519 524
,r
Vapor-phase stoichiometry and heat treatment
of CdTe starting material for physical vapor transport
Ching-Hua Sua'*, Yi-Gao Sha a' t, S.L. Lehoczky a, Hao-Chieh Liu b, Rei Fang b,
R.F. Brebrick b
.Space Sciences Laboratory. NASA/Marshall Space Flight Center, Huntsville, AL 35812, USA
hMaterials Science and Metallurgy Program, Marquette UniversiO', Milwaukee, W753233, USA
Received 19April 1997; accepted 18August 1997
Abstract
Six batches of CdTe, having total amounts of material from 99 to 203 g and gross mole fraction of Te, Xvc,
0.499954- 0.500138, were synthesized from pure Cd and Te elements. The vapor-phase stoichiometry of the as-
synthesized CdTe batches was determined from the partial pressure of Te2, Ptc,, using an optical absorption technique.
The measured vapor compositions at 870"C were Te-rich for all of the batches with partial pressure ratios of Cd to Te2,
Pcd,/Ptc_, ranging from 0.00742 to 1.92. After the heat treatment of baking under dynamic vacuum at 870"C for 8rain, the
vapor-phase compositions moved toward that of the congruent sublimation, i.e. Pcd/PT_ = 2.0, with the measured
Pca/Pv,., varying from 1.84 to 3.47. The partial pressure measurements on one of the heat-treated samples also showed
that the sample remained close to the congruent sublimation condition over the temperature range 800 880_C. _, 1998
Elsevier Science B.V. All rights reserved•
!. Introduction range from Group II saturation to Group VI satu-
ration l1 3]. As a result, the transport rate of the
The partial pressures of the species I1 and VI2 in vapor species in the physical vapor transport (PVT)
equilibrium with the II VI semiconducting com- process can also vary from a maximum transport
pounds, at a fixed temperature, can vary over rate corresponding to the condition of congruent
orders of magnitude as the composition of the sublimation for the solid phase to Iransport rates
compound varying over the narrow homogeneity which are orders of magnitude Iower when the solid
composition deviates significantly from congruent
sublimation. A precise control on the stoichiometry
of the starting compound from the weighing of
*Corresponding author. Fax: + I 205 544 8762; c-mail:
the constituent elements is practically impossible.
[email protected].
Nevertheless, with certain heat-treatment methods
Universities Space Research Association, Current address:
Digirad Corporation, 7408 Trade St., San Diego, CA 92121- the partial pressures over the starting compound
2410, USA. material can be reasonably reproduced for the
0022-0248/98/$19.00 _, 1998 Elsevier Science B.V. All rights reserved.
PII S002 2-0248(97)00504-6
520 Ching-HuaSuet al./Journal ofCo'stal Growth183(1998)519 524
congruent sublimation condition. One of the zone refined (QZR), six nine grade, 7 mm diameter
methods to adjust the stoichiometry of the starting Cd rods and QZR, six-nine grade Te bars from
material is to bake out the material at the process- Johnson Matthey, Inc. The Cd bars were cut into
ing temperature under a dynamic vacuum con- approximately 1.5cm segments and the Te bars
dition. However, the effectiveness of the heat were cut into chunks with typical linear dimensions
treatment on the vapor-phase composition was of 2-4 mm. The elements were weighed to an accu-
never reported nor confirmed. The direct way racy of 0.1 rag. The ampoules were sealed under
to determine vapor-phase stoichiometry is by vacuum after the elements had been loaded with
measurement of the partial pressures coexisting the Cd rods surrounded by the Te chunks. The
with the sample. Using an optical absorption tech- amounts of Cd and Te in each ampoule as well as
nique, Brebrick and co-workers have reported par- the corresponding gross Te mole fraction are listed
tial pressure data over the systems of HgTe [4, 5], in Table 1.The sealed ampoules were heated inside
HgSe [6], CdTe [3, 7], ZnTe [2], ZnSe [8, 9], PbTe a furnace with an isothermal heat-pipe liner from
[10,11], SnTe [12, 13], PbSnTe [13], HgCdTe room temperature to the homogenization temper-
[14-16] and HgZnTe [17]. In this paper, using the atures, TH, in several hours and maintained at
same optical absorption technique, we report the TH for certain hours before cool down. On batch
effectiveness of the heat treatment by measuring the # 6the furnace was heated from room temperature
partial pressures of Te2, Pve,, over a series of as- to 500°C in 1h and maintained at 500_C for 22 h
synthesized CdTe samples as well as Pve2 over these before being heated to 925°C in 2h. The homogen-
samples after they have been heat treated under ization temperature, Tn, and the time at Tn are
dynamic vacuum. also listed in Table 1. During heat-up the homo-
genization reaction takes place at the CdTe Te
eutectic temperature of 447.2°C [18]. The readings
2. Experimental procedure of the thermocouple attached to the ampoule
jumped from 450°C to over 500°C (600°C on batch
2.1. Homogenization of CdTe # 11) within 1min because of the heat from the
exothermic eutectic reaction.
The ampoules were made from either 27x 25
(27 mm OD, 25 mm ID), 23 x 20 or 22 x 20mm 2.2. Heat treatment and partial pressure
fused silica tubings supplied by Heraeus Amersil, measurements
Inc. The ampoules were cleaned and outgassed at
1045°C under vacuum for over 16 hand, except for After the homogenization process, the ampoule
batch # 13, were then graphitized inside by flowing for each batch was opened and the reacted sponge-
a mixture of 10% methane-Ar gas at 1045°C for like CdTe was crushed, ground and mixed with
5-10 min. The starting elements were quadruple mortar and pestle into particles of diameter less
Table 1
Amounts ofCdand Te,_becorresponding Teeonlen_,_hehomogenization lemperalure, 7",,and thehomogenization duration fore_cb
balch
Batch number Cd (gj Te(g) Xr, - -_ Tn (°C) Tn (h)
6 61.1715 69.4311 --4.6x10-2 925 63
7 71.1613 80.7791 --1.7×10-2 925 16
9 64.3485 73.0792 9.8×10-_ 955 64
10 77.0927 87.5088 - 2.6×10-2 1015 39
11 95.1116 107.9900 3.8×I0-s 985 40
13 46.5623 52.8885 13.8×10-5 940 21
Ching-Hua Suet al. /Journal of Crystal Growth 183 (1998) 519 524 521
than 0.5 ram. The T-shape cells for the optical ab- sample, located at the bottom of the vertical leg of
sorption measurement were made of fused silica the T-shaped cell, was held at one of a set of
with path lengths varying from 18 to 30 mm. The temperatures lower than the optical path temper-
cells were cleaned and outgassed at 1000-1030°C ature. The optical absorbance was measured be-
for over 16h before loading the samples. One set of tween 190 and 800 nm and the partial pressures of
the optical cells was loaded with the a.s-synthesized individual vapor species were calculated using the
material from various batches and sealed under data determined from the calibration runs with
vacuum. The other cells were loaded with the as- pure elements in the cells. As mentioned in the
synthesized materials followed by a heat-treatment Introduction, the predominant vapor species in
process to adjust the stoichiometry prior to seai off. equilibrium with condensed CdTe are Cd and Te2.
The heat treatment of these cells was performed by All other thermodynamically possible Te monomer
baking out the loaded cell at the processed temper- or polymers have partial pressures at least two
ature under dynamic vacuum. Table 2 lists the cell orders of magnitude lower than that of Te2 under
number (corresponding to the CdTe batch), the the processing temperature and condition. There-
amounts of CdTe loaded, the bake-out temperature fore, only the Te dimer will be considered in the
and the bake-out duration for each optical cell. The measurements of stoichiometry. For all the cells the
amounts of CdTe as well as the bake-out temper- measurements indicated that the samples were
atures were selected to match the parameters usu- either Te-rich or near congruent sublimation. Un-
ally employed in our laboratory for the crystal der these conditions the 238.7 nm atomic Cd ab-
growth of CdTe by physical vapor transport. The sorption peak was not strong enough to give
loss of the material during the baking process un- accurate measurements of Pea. The partial pres-
der vacuum was reasonable. After baking at 870°C sures of Te2 were taken as the average of several
for 8min the loss of a typical 18g charge of CdTe values calculated from the Beer's law constants
was 1.8g, i.e. about 10%. established in the calibration runs of pure Te for the
The basic principles for the partial pressure wavelengths between 363.4 to 537.2 nm [16]. For
measurements and the experimental procedure each cell the partial pressure of Te2 was measured
have been described in detail in Refs. [2-17]. In while the sample was held at 870°C and the optical
brief, the sample beam of a double-beam mono- cell was at 900°C. The base line was established
chromator travelled along the top of a constant with the sample at 400°C. Each cell was held at an
temperature T-shaped cell and passed through 870°C sample temperature for at least 24 h prior to
the optical windows. During measurements, the the measurements.
Table 2
Amounts of CdTe loaded, heat-treatment conditions, the measured partial pressure of Te2, PT_:, and the calculated pressure ratio,
PCd,/Pr_:, at 870°C for as-synthesized and heat treated batches
Cell Amount of CdTe (g) Heat-treatment Heat-treatment P'ro, (arm) Pca/Px_2
temperature (_C) duration (min) at 870-C at 870°C
6 15.0 4.06x 10 3 1.92
7 15.0 1.65 × 10-1 0.00742
7A 13.0 870 8 3.44 × 10- 3 2.47
9 12.4 - 8.90× 10-z 0.0187
10 14.9 4.95× 10-3 1.43
10A 20.3 870 8 2.74 ×10- _ 3.47
11 6.9 - 1.51 ×10-2 0.268
I1A 20.0 860 8 2.96 x 10-3 3.11
13A 17.9 800 8 4.18 x 10-3 1.84
522
Ching-Hua Suet al. / Journal of C_3'stal Growth 183 ('1998) 519 524
3. Results was increasing to above 880_C before the sample
was cooled to 795_C. The second series of measure-
The measured partial pressure of Te2 at 870_C ments is shown as solid squares and agreed well
for each optical cell is given in the 5th coIumn of with the results of the first series. The time between
Table 2. The given values were usually the average each run is also given in the figure. The solid line
of two measurements obtained after the cells were shown is the PT¢., for the congruent sublimation
at temperature for 24 and 48 h. The corresponding condition, i.e. Pcd/PT,_ = 2.0.
partial pressures of Cd can be obtained from the
stoichiometric invariant, AGf, the Gibbs energy of
formation of CdTe from the vapor phase [19]: 4. Discussion
AG,- = RT In(P(.dP[,._)
The measured partial pressures of Te2 over vari-
= - 68 640 + 44.94T (cal/mol). (l) ous as-synthesized CdTe batches, having total
amounts of material from 99 to 203 g and gross Te
The stoichiometry of the vapor phase at 870"C, mole fraction, XT_, from 0.499954 to 0.500138,
defined as Pca/PT¢:, was then calculated for each show that the vapor compositions at 870_C were
cell using the measured PT_: and the calculated always Te-rich. The PT_ in equilibrium with four
Pcd and is given in the last column of Table 2. CdTe samples of known condensed-phase com-
The vapor-phase stoichiometry at temperatures positions have previously been measured over the
other than 870°C was also measured for cell 10A temperature range 635 1025_C [7]. The measured
and is plotted in Fig. 1.The first series of measured PTe;. at 870_C and the corresponding Te contents
PT_: is shown as open circles and was started at for these four samples were scaled from Figs. 2 and
about 825'_C (1000/T =0.91). Several measure- 4 of Ref. [7], respectively, and are tabulated in
ments were taken when the sample temperature Table 3. By comparing the measured PT_: of our
10-_ [ " i -
8800C 800"C
AE .._... congruent
sublimation
10*
"6
_3.5 h
o')
U)
n 103
_2
(o
1"r5 h"m_40_
0.80 0.85 0.90 0.95 1.00
1000/T (K)
Fig. I. The measured Pr_: as a function of 1000,'T for cell 10A. The first series of measured P_: isshown as open circles and was started
at about 825-C (I000/T = 0.91). Several measurements were taken when the sample temperature was increasing to above 880-C before
thc sample was cooled to 795-C. The second series of measurements isshown as solid squares. The time between each run isalso given.
Ching-Hua Su et al. /Journal of Crystal Growth 183 (1998) 519 524 523
Table 3 that of congruent sublimation during the 8min
Te mole fraction, XT, and measured PTc_ at 870"C for CdTe bake out even when the starting composition was
samples from Ref. [7] near the Te-saturated condition such as the case of
cell # 7. The change in composition stopped when
Samples XT_ -- _ PTej (atm)
the sample reached the congruent sublimation con-
CT-93E 4.4 x 10-S 0.135 dition because the sample started to lose Cd and Te
CT-92A 2.2 x 10-_ 0.105 at the same rate through the sublimation process.
CT92-C 1.4 x 10- n 0.0595
The required baking time can be estimated from the
CT92-D 1.2 x 10- _ 0.0306
CdTe interdiffusion coefficient reported by Brown
Congruent sublimation" 0.3 x 10- s 0.00396
et al. [21] which gave Dcdw = 3.4 x 10- scma/s at
"Ref. [20]. 870°C. The estimated diffusion length (Dr) L'2 for
8min annealing time is 0.128 cm, which is about
5 times the radius of the ground particle. Also,
as-synthesized samples with those in Table 3,it can although the heat treatment was performed at
be concluded that (a) the samples in cell # 6 and 870"C the heat-treated sample remains close to the
# 10 were near the congruent sublimation com- congruent sublimation condition in the temper-
position at 870°C (from a defect chemistry analysis, ature range 800-880°C as indicated in Fig. 1.This
[20], this congruent sublimation composition was also evident from the defect chemistry analysis
is (XT_-½) = 0.3x 10-s); (b) having P1"_= in Ref. [20]; the congruent sublimation composi-
0.165atm at 870_C the sample in cell 27 was tion almost follows a constant Xx_ curve for tem-
almost Te-saturated with (X_-c- ½) greater than peratures below 900°C.
4.4x10 -5 (note: the equilibrium PTe_ for Te-
saturated condition at 870=C is 0.18 atm [7]); (c)
the sample in cell 29, with the measured Acknowledgements
Pve2 =0-089atm at 870°C, has composition
(Xve - ½)in the range 1.4 2.2 x 10-5; (d) the CdTe The work was supported by the Microgravity
in cell # 10 and # 11 have (X_re- ½)values below Research Division of the NationaI Aeronautics and
1.2 x 10-5 and above that for congruent sublima- Space Administration.
tion, i.e. (XT, - ½)= 0.3 x 10-5, with the value for
cell # 10 lower than that for cell # 11. A possible
cause for the Te-rich nature of the as-synthesized References
CdTe samples is that during the grinding of the
synthesized material, occasionally, a small smear of [1] R.C. Sharma, Y.A. Chang, J. Crystal Growth 88(1988) 193.
unreacted Cd element was found and was taken out. [2] RF. Brebrick, J. Electrochem. Soc. 116 (1969) 1274.
Table 2 clearly shows that after the heat treat- [3] RF. Brebrick, J. Electrochem. Soc. 118 (1971) 2014.
[4] R.F. Brebrick, A.J. Strauss, J. Phys. Chem. Solids 26(1965)
ment under dynamic vacuum, the vapor-phase
989.
compositions moved toward that of congruent sub- [5] C.-H. Su, P.2K Liao, T. Tung, R.F. Brebrick, High Temp.
limation with the measured Pc_/PT_ varying from Sci. 14 (1981) 181.
1.84 to 3.47. The error associated with the meas- [6] R.F. Brebrick, J. Chem. Phys. 43 (1965) 3846.
[7] R. Fang, RF. Brebrick, J. Phys. Chem. Solids 57 (1996)
ured Pr_ is estimated to be 15%. With the same
443.
error assumed for the AGf given in Eq. (1), the
[8] Y.-G. Sha, C.-H. Su, W. Palosz, M.P. Volz, D.C. Gillies,
experimentally measured Pca/PT_: for a congruent- F.R. Szofran, S.L. Lehoczky, H.-C. Liu, R.F. Brebrick, J.
ly subliming CdTe sample would be in the range Crystal Growth 146 (1995) 42.
1.38-2.93. The rate-controlling step for the heat [9] C.-H. Su, Y.-G. Sha, K. Mazuruk, S.L. Lehoczky, H.-C.
treatment should be the solid-state diffusion inside Liu, R. Fang, RF. Brebrick, J. Crystal Growth 166 (1996)
736.
each CdTe particle. The composition of the sample
[113] Y. Huang, R.F. Brebrick, J. Electrochem. Soc. 135 (1988)
in each cell changed from its original value as 486.
outlined in the last paragraph to a value close to [11] R.F. Brebrick, A.J. Strauss, J. Chem. Phys. 40 (1964) 3230.
524
Ching-Hua Suet al. /Journal of Co'stal Growth 183 (1998) 519 524
[12] R.F. Brebrick, A.J. Strauss, J. Chem. Phys. 41 (1964) [17] K.-T. Chen, Y.-G. Sha, R.F. Brebrick, J. Vac. Sci. Technol.
197. A 8 (1990) 1086.
[13] Y. Huang, R.F. Brebrick, J. Electrochem. Soc. 135 (1988) [18] RF. Brebrick, C.-H Su, P.-K. Liao, Semiconductors and
1547. Semimetals, voI. 19, Ch. 3, Academic Press, New York,
[14] J.P. Schwartz, T. Tung, R.F. Brebrick, J. Electrochem. Soc. 1983.
128 (1981) 438. [19] R.F. Brebrick, A.J. Strauss, J. Phys. Chem. Solids 25(1964)
[15] T. Tung, L. Golonka, R.F. Brebrick, J. Electrochem. Soc. 1441.
128 (1981) 451. [20] R.F. Brebrick, R. Fang, J. Phys. Chem. Solids 57 (1996) 451.
[16] C.-H. Su, P.-K. Liao, R.F. Brebrick, J. Electrochem. Soc. [21] M. Brown, A.F.W. Willoughby, J. Crystal Growth 59
132 (1985) 942. (1982) 27.
Journal of Crystal Growth
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