Real-Time Spectroscopic Ellipsometry for Flux Calibrations in Multi-Source Co-Evaporation of Thin Films: Application to Rate Variations in CuInSe2 Deposition
Abstract
:1. Introduction
2. Materials and Methods
3. Results
3.1. Real-Time Spectroscopic Ellipsometry: Cu and In2Se3 Calibration Depositions
3.2. Cu and In Flux Analysis
3.3. Development of Source Calibration for CIS Deposition
3.4. Atomic Concentration Corrections in Source Calibration for CIS Deposition
3.5. Structural and Photoelectronic Properties for CIS Films Deposited at Different Rates
4. Discussion
4.1. Calibration of CIS Deposition
4.2. Effect of Deposition Rate on the Properties of CIS
5. Summary
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Conflicts of Interest
References
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Material and Its Thin Film Deposition Temperature T | Crystal Structure | Lattice Parameters at 20 °C [Ref.] (Å) | Number of Metal Atoms per Unit Cell | Concentration of Metal Atoms at RT (Å−3) | Thermal Expansion Coefficient α(T) = P1 (10−6 K−1) + P2 (K)/T2 [Ref.] | Concentration of Atoms at Temperature T (Å−3) |
---|---|---|---|---|---|---|
Cu T = 20 °C | face-centered cubic | a = 3.6147 [23] | 4 | 0.084692 | P1 = 14.87 [23] | 0.084692 |
In2Se3 T = 570 °C | defect wurtzite | a = 7.1236 c = 19.381 [25] | 12 | 0.014069 | P1(a) = 5; P1(c) = 16 P2(a) ~ 0; P2(c) ~ 0 [26] | 0.013869 |
CuInSe2 T = 570 °C | chalco- pyrite | a = 5.7810 c = 11.6422 [27] | Cu: 4y In: 4 (assumed) | Cu: 0.010281y In: 0.010281 | P1(a) = 9.15; P1(c) = 7.61 P2(a) ~ 0; P2(c) ~ 0 [28] | Cu: 0.010135y In: 0.010135 |
Material, m, and Indept. Variable | cm,0 (°C) or dm,0 (°C) | cm,1 (°C s/Å) or dm,1 (°C Å2 s) | cm,2 (°C s2/Å2) or dm,2 (°C Å4 s2) | cm,3 (°C s3/Å3) or dm,3 (°C Å6 s3) |
---|---|---|---|---|
Cu; Reff,Cu,Cu | 1.29980 × 103 | 9.59360 × 101 | 2.00584 × 101 | −2.30861 × 101 |
Cu; FCu | 1.29980 × 103 | 1.13276 ×103 | 2.79648 × 103 | −3.80034 × 104 |
In2Se3; Reff,In,In2Se3 | 8.40985 × 102 | 6.85232 × 101 | −1.05532 × 101 | 6.57389 × 10−1 |
In; FIn | 8.40985 × 102 | 4.94075 × 103 | −5.48649 × 104 | 2.46426 × 105 |
Material, m, and property | am,0 (Å s−1) or bm,0 (Å−2 s−1) | am,1 (Å s−1 °C−1) or bm,1 (Å−2 s−1 °C−1) | am,2 (Å s−1 °C−2) or bm,2 (Å−2 s−1 °C−2) | am,3 (Å s−1 °C−3) or bm,3 (Å−2 s−1 °C−3) |
---|---|---|---|---|
Cu; Reff,Cu,Cu | −1.54970 × 103 | 3.44158 × 100 | −2.55428 × 10−3 | 6.33745 × 10−7 |
Cu; FCu | −1.31247 × 102 | 2.91475 ×10−1 | −2.16327 × 10−4 | 5.36731 × 10−8 |
In2Se3; Reff,In,In2Se3 | 2.68050 × 102 | −5.96550 × 10−1 | 3.33333 × 10−4 | -- |
In; FIn | 3.71758 × 100 | −8.27355 × 10−3 | 4.62300 × 10−6 | -- |
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Sapkota, D.R.; Ramanujam, B.; Pradhan, P.; Alaani, M.A.R.; Shan, A.; Heben, M.J.; Marsillac, S.; Podraza, N.J.; Collins, R.W. Real-Time Spectroscopic Ellipsometry for Flux Calibrations in Multi-Source Co-Evaporation of Thin Films: Application to Rate Variations in CuInSe2 Deposition. Materials 2024, 17, 4048. https://doi.org/10.3390/ma17164048
Sapkota DR, Ramanujam B, Pradhan P, Alaani MAR, Shan A, Heben MJ, Marsillac S, Podraza NJ, Collins RW. Real-Time Spectroscopic Ellipsometry for Flux Calibrations in Multi-Source Co-Evaporation of Thin Films: Application to Rate Variations in CuInSe2 Deposition. Materials. 2024; 17(16):4048. https://doi.org/10.3390/ma17164048
Chicago/Turabian StyleSapkota, Dhurba R., Balaji Ramanujam, Puja Pradhan, Mohammed A. Razooqi Alaani, Ambalanath Shan, Michael J. Heben, Sylvain Marsillac, Nikolas J. Podraza, and Robert W. Collins. 2024. "Real-Time Spectroscopic Ellipsometry for Flux Calibrations in Multi-Source Co-Evaporation of Thin Films: Application to Rate Variations in CuInSe2 Deposition" Materials 17, no. 16: 4048. https://doi.org/10.3390/ma17164048