Surface passivation of InAs(001) with thioacetamide

Abstract

Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. We describe the passivation of InAs͑001͒ surfaces with thioacetamide ͑CH 3 CSNH 2 or TAM͒ as an alternative to the standard sulfur passivation using inorganic sulfide ͑NH 4 ͒ 2 S x . Quantitative comparison using x-ray photoelectron spectroscopy ͑XPS͒ demonstrates that TAM passivation dramatically improves the stability against reoxidation in air compared with the inorganic sulfide, with little to no etching during the treatment. We find that TAM passivation preserves the intrinsic surface charge accumulation layer, as directly confirmed with laser-induced photoemission. Overall, TAM appears to provide superior passivation for electronic device and sensing applications.

Passivation of GaSb and InAs by pH-activated thioacetamide

“…Sulfur passivation has been used effectively to passivate exposed surfaces of III-V semiconductor devices [15][16][17][18][19][20][21][22][23][24][25], and has been previously attempted for T2SLs [2][3][4]7]. Historically, most common sulfur passivation treatments have been performed in aqueous solutions of inorganic sulfides, such as (NH 4 ) 2 S x [16,17,23,[26][27][28] or Na 2 S [18,26,27,29].…”

Quantification of discrete oxide and sulfur layers on sulfur‐passivated InAs by XPS

“…The first method is to use the S 2p/As 3d intensity ratio ( Table 3). Because of the S 2p and As 3d peak properties discussed in the previous section, this ratio is the best model-independent, semiquantitative measure of the S coverage, 11 even for samples with unknown distribution of elements in the top few atomic layers. The second method is to use In 3d and S 2p peaks for a quantitative coverage estimate.…”

“…The application of the DL model for quantitative comparison between the TAM passivation and the (NH 4 ) 2 S x benchmark is reported elsewhere. 11 . WORK UNIT NUMBER…”

On the processing of InAs and InSb photodiode applications

“…By using chemical passivation techniques one aims to terminate those dangling bonds into a stable configuration that would resist oxidation and contamination. Electronic expectations are to unpin the Fermi level, reduce surface band bending and achieve a flat band state at the surface relative to the bulk [5][6][7][8].…”