Chemical preparation of GaSb(001) substrates prior to MBE

Abstract

The chemical preparation of GaSb (001) substrates was performed by Br2-HCI-HN03-CH3COOH solution. The removed layer thickness was evaluated a s a function of the constituent concentrations and the etching time. The surface quality was controlled by SEM, RHEEO and AES. With this treatment, excellent surface morphology of substrates and growth film is obtained.

In-situ Reflectance Monitoring of GaSb Substrate Oxide Desorption

“…The solvent degrease consisted of hot trichloroethylene, followed by acetone and then 2-propanol. The etch procedure was 3 min of agitation in HC1, or HCl followed by an additional 30 s etch in Br2-HCI-HN0,-CH,COOH [16]. Substrates were then rinsed in one of three different solutions: 2-propanol, methanol, or deionized water @I H20), and blown dry with N2.…”

Preparation of GaSb substrates for GaSb and GaInAsSb growth by organometallic vapor phase epitaxy

“…Surface roughness and impurity contamination have been correlated with poor surface morphology, interfacial carrier accumulation (or depletion), and interface states, all of which negatively impact material quality and device performance [1][2][3][4][5][6]. While the use of epiready GaAs and InP substrates may be considered more routine [7], epiready GaSb substrates had a rougher surface morphology after thermal desorption of the oxide layer compared to ones that had been first prepared by chemically etching in HCl and then thermally cleaned [6].…”

“…The oxidation rate of GaSb is significantly larger than that of GaAs [9], and oxide formation appears unavoidable even when samples are prepared in an N 2 -purged glove box [3]. Therefore, thermal cleaning in vacuum, H 2 , or under an Sb flux is used to desorb residual gallium and antimony oxides [1][2][3]6].…”

“…Therefore, thermal cleaning in vacuum, H 2 , or under an Sb flux is used to desorb residual gallium and antimony oxides [1][2][3]6]. Although the ambient may affect the kinetics of oxide desorption, oxidefree surfaces were reported to be complete at temperatures between 480 C and 550 C [1][2][3].…”

Atomic hydrogen cleaning of GaSb(001) surfaces

“…Although thermal desorption of the native oxide layer can be achieved in ultrahigh vacuum by annealing to 600°C under a Sb 4 overpressure, this process results in significant surface roughening. 11 Several cycles of low energy argon ion bombardment and annealing have also been shown to produce clean, ordered ͑1ϫ3͒ surfaces. 12,13 However, in related III-V materials, this latter treatment results in a high degree of residual electronic damage that cannot be repaired by annealing.…”