Fabrication of Long Wavelength Array by In-Situ Molecular Beam Epitaxy.
Abstract
In this reporting period, we have designed and constructed the major components of a MBE system for fabrication of long wavelength IR (LWIR) detector arrays. Among these components, the high temperature effusion cells were specially designed for alkaline earth fluoride (CaF2 and BaF2) growth. In the meantime, several multiple-layered fluoride films were grown on Si substrate to test out their crystallinities. The purpose of introducing the fluoride epilayers in this project is to form a buffer layer to accommodate a large lattice mismatch between LWIR detector layer and Si substrate. Since the growth of fluoride epilayers requires high source temperature (1200 deg C - 1300 deg C) to obtain reasonable growth rates (0.3 - 2A/sec), the specially designed effusion cell has been made. Fig. 1 shows the designed structure of the high temperature effusion cell. The power consumption of the high temperature effusion cell, shown in Fig. 1, has been measured and the results are plotted in Fig. 2 vs. the cell temperature. The shadowed area provides the applicable cell temperature ranges required for the fluoride epilayer growth. Our data show that the power consumption corresponding to the shadowed area is still at a feasible level.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 12, 1994
- Accession Number
- ADA288599