Development of Process to Produce Wafer Scale Zinc Selenide (ZnSe) Crystals

This technology program focuses on producing wafer level single crystals of Zinc Selenide (ZnSe). ZnSe is a good alternative to currently used materials (such as periodically poled lithium niobate (PPLN) or quasi phase-matched GaAs structures), for infrared countermeasure applications. ZnSe has a wider band gap, modest nonlinear coefficient, and high transparency from visible to long IR wavelengths. Unfortunately, there exists a lack of high-quality large single crystal ZnSe substrates. We propose a commercial, scalable single crystal growth process for large diameter ZnSe substrates using Physical Vapor Transport (PVT). The Brimrose team has extensive hands-on experience in the growth of ZnSe and similar semiconductors by PVT. PVT inherently has a slow growth rate. However, we have put a great deal of effort into understanding the parameters to enhance the transport rate and have demonstrated the feasibility to do so. Using our novel, proprietary, modified materials processing technique, we routinely produce high quality, single crystals of ZnSe up to 15mm in diameter.  We will further scale up the size during Phase I and Phase II. We will use unseeded growth of ZnSe crystal to prepare oriented seeds for seeded growth to obtain oriented single crystals.