In-situ dry etching of InP using phosphorus trichloride and regrowth inside a chemical beam epitaxial growth chamber

Chemical Beam Etching Reactions of PCl3 on GaAs(100)

“…(i) PCl 3 , GaCl, P 4 , and As 2 are the major thermal desorption products obtained on adsorption at room temperature. These products all desorb below 650 K. This is consistent with the results of Tsang et al, who found that etching was optimum for temperatures ≥ 530 °C (800 K).…”

“…Tsang et al , have already shown that PCl 3 is a suitable chemical beam etchant of InP, and etching with this compound produced surfaces of smooth and textureless morphologies at high temperatures (>530 °C) and low etch rates. The surface reaction mechanisms elucidated in this study show that PCl 3 reacts with the GaAs surface to produce volatile GaCl species and, hence, can also be utilized in the etching of GaAs under optimum conditions.…”

“…A solution to this problem would be to use molecules that could do both, and in situ growth/etching steps could be performed without the need for switching beam fluxes or moving samples from one chamber to another. The work of Tsang et al has shown that molecules such as PCl 3 and AsCl 3 can be used as chemical beam etchants in a semiconductor growth chamber for etching and regrowth of InP and GaAs, respectively. These molecules are made up of halogen atoms, required for etching compound semiconductors, and a group V element, making them ideal as chemical beam etchants inside a semiconductor growth chamber.…”

“…Although PCl 3 , AsCl 3 , ,, and AsBr 3 15 have been shown to be good chemical beam etchants for compound semiconductors, to date, no detailed surface mechanistic studies of the layer-by-layer etching process of these group V halides have been performed. Tsang et al ,, used RHEED oscillations to demonstrate the layer-by-layer etching with molecular beams of PCl 3 and AsCl 3 , while Zhang et al used modulated molecular beam studies to derive kinetic information and identify reaction products during etching of GaAs(100) with AsBr 3 .…”

“…Although PCl 3 , AsCl 3 , ,, and AsBr 3 15 have been shown to be good chemical beam etchants for compound semiconductors, to date, no detailed surface mechanistic studies of the layer-by-layer etching process of these group V halides have been performed. Tsang et al ,, used RHEED oscillations to demonstrate the layer-by-layer etching with molecular beams of PCl 3 and AsCl 3 , while Zhang et al used modulated molecular beam studies to derive kinetic information and identify reaction products during etching of GaAs(100) with AsBr 3 . Further experiments on AsBr 3 etching of GaAs(100) using RHEED oscillations to monitor the etching and computer simulations of the atomistic (Monte Carlo) models of the etching process , have revealed that the process is temperature dependent, and physical effects such as surface morphology and kinetics of the atomistic processes play important roles in the overall etching mechanism.…”