TY - JOUR
T1 - Effects of reactive ion etching on GaAs/AlGaAs heterostmctures
AU - Guggina, W. H.
AU - Ballegeer, D. G.
AU - Adesida, I.
N1 - Funding Information:
The authors would like to thank Prof. G. Stillman for the use of his laboratory for Hall effect measurements. This work was supported by NSF Grant ECD 89-43166, JSEP N00014-90-J-1270, and NSF Grant DMR 89-20538.
PY - 1991/7/1
Y1 - 1991/7/1
N2 - The effects of selective reactive ion etching (SRIE) in SiCl4: SiF4 plasmas on modulation-doped GaAs/Al0.3Ga0.7 As heterostructures have been investigated. Hall effect measurements were conducted to determine SRIE effects on carrier mobility and electron sheet concentration of the two-dimensional electron gas (2-DEG). Samples were etched at several plasma self-bias voltages and for extended etch periods with Hall effect measurements conducted at 300 and 77 K. Results show reductions in the 2-DEG carrier concentration and mobility with increasing plasma self-bias voltage and increasing etch time at both room and liquid-nitrogen temperatures. The reduction in electron concentration after etching can be attributed to the creation of traps in the AlGaAs donor layer due to bombardment with the low-energy ions present in the plasma. Mobility reduction is due to the increasing importance of remote impurity scattering as electron sheet concentration decreases. These degradations in electron concentration and mobility are sufficiently minimized for low plasma self-bias voltages (-30 V), and short etch time such that the SRIE process should be useful for fabricating modulation-doped field-effect transistors.
AB - The effects of selective reactive ion etching (SRIE) in SiCl4: SiF4 plasmas on modulation-doped GaAs/Al0.3Ga0.7 As heterostructures have been investigated. Hall effect measurements were conducted to determine SRIE effects on carrier mobility and electron sheet concentration of the two-dimensional electron gas (2-DEG). Samples were etched at several plasma self-bias voltages and for extended etch periods with Hall effect measurements conducted at 300 and 77 K. Results show reductions in the 2-DEG carrier concentration and mobility with increasing plasma self-bias voltage and increasing etch time at both room and liquid-nitrogen temperatures. The reduction in electron concentration after etching can be attributed to the creation of traps in the AlGaAs donor layer due to bombardment with the low-energy ions present in the plasma. Mobility reduction is due to the increasing importance of remote impurity scattering as electron sheet concentration decreases. These degradations in electron concentration and mobility are sufficiently minimized for low plasma self-bias voltages (-30 V), and short etch time such that the SRIE process should be useful for fabricating modulation-doped field-effect transistors.
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U2 - 10.1016/0168-583X(91)95753-Z
DO - 10.1016/0168-583X(91)95753-Z
M3 - Article
AN - SCOPUS:44949272869
VL - 59-60
SP - 1011
EP - 1014
JO - Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms
JF - Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms
SN - 0168-583X
IS - PART 2
ER -