OUSD (R&E) CRITICAL TECHNOLOGY AREA(S): Microelectronics The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), 22 CFR Parts 120-130, which controls the export and import of defense-related material and services, including export of sensitive technical data, or the Export Administration Regulation (EAR), 15 CFR Parts 730-774, which controls dual use items. Offerors must disclose any proposed use of foreign nationals (FNs), their country(ies) of origin, the type of visa or work permit possessed, and the statement of work (SOW) tasks intended for accomplishment by the FN(s) in accordance with the Announcement. Offerors are advised foreign nationals proposed to perform on this topic may be restricted due to the technical data under US Export Control Laws. OBJECTIVE: Achieve larger CdZnTe substrate size (150 mm or greater) through improvements in ampoule and crucible design as well as develop automated processes for sealing the ampoule containing the CdZnTe charge to increase production capacity. DESCRIPTION: Infrared detectors made with HgCdTe provide the Government with high sensitivity for many missile-defense applications. HgCdTe deposited by molecular beam epitaxy (MBE) is currently grown on commercially available, (211) oriented CdZnTe substrates with sizes up to 7x7.5 cm. These substrates are typically made from 125 mm diameter CdZnTe boules grown using the Vertical Gradient Freeze (VGF) process. The problem is scaling up reactor diameter to allow for larger diameter boules and thereby larger size CdZnTe substrates. This topic is focusing not on the VGF reactor itself but improving the sub-components to allow these larger reactors to be produced. The Government is seeking innovative ideas for improvements to the VGF CdZnTe growth package. These improvements should address: 1. High purity quartz and PBN component tolerances (wall thickness, circularity, etc.) 2. Automation and thermal management of the vacuum seal-off 3. Modifications to the growth package to support increasing reliability and safety A complete solution encompassing all three areas is preferred but not required. Many of these challenges are limited by current quartz and PBN manufacturability. A reusable VGF CdZnTe component package would be ideal but is not required. Please note that this topic is focused on improving our capability to grow high purity, bulk, single-crystal CdZnTe material, which would then be further processed into substrates for long-wave infrared (LWIR) detector arrays. Solutions related to processing bulk-material into CdZnTe substrates (e.g., wire sawing, dicing, grinding, lapping, polishing) are outside the scope of this topic. Proposals should include a number of innovations that, as a whole, would significantly push the SOA. Proposed solutions should also be compatible with all the material specifications and safety requirements of a SOA commercial CdZnTe foundry. PHASE I: Study the scientific and technical feasibility of the proposed approach. Collaborate with government agencies and industry (e.g., CdZnTe foundries and detector manufacturers) to develop requirements. Conduct research, analyses, and experimentation as needed to demonstrate feasibility and/or validate models. Develop preliminary designs for any new equipment, if applicable. Complete cost and performance assessments and compare to existing SOA approaches. Identify risk areas and mitigation plans that would be implemented in Phase II. Responders to this topic are strongly encouraged to team with existing CdZnTe boule manufacturers. Complete a plan for Phase II and contact CdZnTe boule manufacturers to verify the plan is executable. PHASE II: Finalize equipment designs and fabricate a prototype, if applicable. Demonstrate the ability to carry out further improvements before they are used for high quality growth of single-crystal CdZnTe boules meeting the topic objectives. Responders to this topic are strongly encouraged to team with existing CdZnTe boule manufacturers. Provide samples to the Government and industry partners for independent assessment. Update models with experimental data and refine the design based on lessons learned. Finalize cost and performance estimates based on these initial results. Collaborate with industry partners to put together a Phase III plan that includes quotes and letters of commitment. PHASE III DUAL USE APPLICATIONS: Transition operation of the growth capability to at least one CdZnTe commercial foundry operator. Provide supporting documentation and training for their operation and maintenance, as required. Process a resulting demonstration boule from the commercial foundry to make several CdZnTe substrates for verification testing to demonstrate quality, consistency and reproducibility of the improved growth capability. Show how the technology can also support CdZnTe growth for other defense and commercial applications (e.g. CdTe solar cells). REFERENCES: 1). "Impact of CdZnTe Substrates on MBE HgCdTe Deposition" J. D. Benson, L. O. Bubulac, M. Jaime-Vasquez, J. M. Arias, P. J. Smith, R. N. Jacobs, J. K. Markunas, L. A. Almeida, A. Stoltz, P. S. Wijewarnasuriya, J. Peterson, M. Reddy, K. Jones, S. M. Johnson, and D. D. Lofgreen, Journal of Electronic Materials 46, (2017). 2). " Impurity Hot Spots' in MBE HgCdTe/CdZnTe" J. D. Benson, L. O. Bubulac, A. Wang, R. N. Jacobs, J. M. Arias, M. Jaime-Vasquez, P. J. Smith, L. A. Almeida, A. Stoltz, P. S. Wijewarnasuriya, A. Yulius, M. Carmody, M. Reddy, J. Peterson, S. M. Johnson, J. Bangs, and D. D. Lofgreen, Journal of Electronic Materials 47, 5671 (2018). 3). "As-Received CdZnTe Substrate Contamination" J. D. Benson, L. O. Bubulac, M. Jaime-Vasquez, C. M. Lennon, P. J. Smith, R. N. Jacobs, J. K. Markunas, L. A. Almeida, A. Stoltz, J. M. Arias, P. S. Wijewarnasuriya, J. Peterson, M. Reddy, M. F. Vilela, S. M. Johnson, D. D. Lofgreen, A. Yulius, M. Carmody, R. Hirsch, J. Fiala, and S. Motakef, Journal of Electronic Materials 44, 3082 (2015). 4). "Analysis of Etched CdZnTe Substrates" J. D. Benson, L. O. Bubulac, M. Jaime-Vasquez, C. M. Lennon, J. M. Arias, P. J. Smith, R. N. Jacobs, J. K. Markunas, L. A. Almeida, A. Stoltz, P. S. Wijewarnasuriya, J. Peterson, M. Reddy, K. Jones, S. M. Johnson, and D. D. Lofgreen, Journal of Electronic Materials 45, 4502 (2016). 5). A. Noda, H. Kurita, and R. Hirano, pp. 21-50 in Mercury Cadmium Telluride Growth, Properties and Applications' Edited by P Capper and J. Garland, Wiley publishing (2011). KEYWORDS: CdZnTe; CZT; Substrate Growth; Ampoule Improvement; Boule Improvement
