UV absorption spectroscopy for monitoring hydride vapor-phase epitaxy of InGaAsP alloys

Abstract

Ultraviolet (UV) absorption spectroscopy has been used to monitor the concentrations of gas-phase reactants participating in the growth of InGaAsP alloys by hydride vapor-phase epitaxy. Room-temperature absorption spectra for PH3, AsH3, and HCl as well as high-temperature (700°C) spectra of InCl, GaCl, PH3,P2, P4, As2, and As4 are presented. For the group V species, the UV absorption bands of the hydride, dimer, and tetramer exhibit considerable overlap, but can still be used to determine the approximate concentration of each species. GaCl and InCl exhibit extremely intense, sharp absorption bands at 248 and 267 nm, respectively. This technique has been used to study the effect of PH3 pyrolysis on InP growth, and to monitor In/Ga ratio for metal transport from an alloy source. This technique can be implemented on reactor systems without reactor design changes and without disturbing the thermal profile by using ‘‘light pipes’’ to probe concentrations of reactive species during growth.

In Situ Growth Analysis

“…Electronic transitions may be observed using a single pass through the growth ambient, while the smaller absorption constants of vibrational transitions usually require a multi-pass configuration. Ultraviolet absorption spectroscopy was most popular for measuring gas-phase concentrations, with an emphasis on alkyl and hydride precursors used in the MOVPE of arsenides [19,20], phosphides [21], and nitrides [22]. Applying Beer's law…”

MR-AQCC study on the ground and low-lying excited states of GaI

“…P emission, in the latter case g e ¼ 2 [34], T 0 e and T 00 e are electronic term values, and R e ðm 0 À m 00 Þ is the TDM between the m 0 and m 00 states (the higher-order moments being assumed to be negligible). The radiative lifetimes of the A 3 …”

“…They have been playing important roles in the development of new semiconductor devices in high frequency and in opto-electronic applications. In chemical vapor deposition techniques such as the Effer process [1], gallium monohalides act as gas phase transporters of semiconductor materials [2][3][4]. There are many experimental and theoretical studies on the ground and low-lying electronic states of gallium monohalides, which have extended and deepened the comprehension about the properties of electronic states of these molecules.…”

Extensive theoretical studies on the low‐lying electronic states of indium monochloride cation, InCl+

“…The monohalides of the Ga and In atoms play important roles in the development of high‐frequency semiconductor devices and opto‐electronic applications 1, 2. Therefore, the detailed interpretation of their electronic and molecular structures deserves great attention.…”