Dry etch damage in GaAs metal-semiconductor field-effect transistors exposed to inductively coupled plasma and electron cyclotron resonance Ar plasmas

1997 ◽  
Vol 15 (4) ◽  
pp. 983 ◽  
Author(s):  
F. Ren
Keyword(s):  
Cyclotron Resonance ◽  
Inductively Coupled Plasma ◽  
Field Effect ◽  
Electron Cyclotron Resonance ◽  
Field Effect Transistors ◽  
Electron Cyclotron ◽  
Inductively Coupled ◽  
Dry Etch

Hydrogenation and Defect Creation in GaAs-Based Devices During High Density Plasma Processing

1998 ◽  
Vol 510 ◽  
Author(s):  
T. Maeda ◽  
J. W. Lee ◽  
C. R. Abernathy ◽  
S. J. Pearton ◽  
F. Ren ◽  
...  
Keyword(s):  
Heterojunction Bipolar Transistors ◽  
Inductively Coupled Plasma ◽  
Electron Cyclotron Resonance ◽  
Field Effect Transistors ◽  
High Electron Mobility Transistors ◽  
High Electron ◽  
Source Power ◽  
Ion Energy ◽  
Inductively Coupled ◽  
Self Bias

AbstractThe effects of Inductively Coupled Plasma (ICP) and Electron Cyclotron Resonance (ECR) H2 plasmas on GaAs metal semiconductor field effect transistors (MESFETs), high electron mobility transistors (HEMTs) and heterojunction bipolar transistors (HBTs) have been measured as a function of ion flux, ion energy and process pressure. The chemical effects of hydrogenation have been compared to direct physical bombardment by Ar plasmas under the same conditions. Si dopant passivation in MESFETs and HEMTs and C base-dopant passivation in HBTs produces much larger changes in sheet resistance, breakdown voltage and device gain or transconductance than Ar ion bombardment and suggests that H2-containing plasma chemistries (CH4/H2 for semiconductor etching, SiH4 for dielectric deposition, CHF3 for dielectric etching) should be avoided, or at least the exposure of the surface minimized. In some cases the device degradation is less for higher source power conditions, due to the suppression of cathode dc self-bias and hence ion energy.

Patterning of LiGaO2 and LiAlO2 by Wet and Dry Etching

1996 ◽  
Vol 449 ◽  
Author(s):  
J. W. Lee ◽  
S. J. Pearton ◽  
C. R. Abernathy ◽  
R. G. Wilson ◽  
B. L. Chai ◽  
...  
Keyword(s):  
Cyclotron Resonance ◽  
High Selectivity ◽  
Electron Cyclotron Resonance ◽  
Dry Etching ◽  
Electron Cyclotron ◽  
Acid Solutions ◽  
Lattice Constants ◽  
Etch Rates ◽  
Dry Etch

ABSTRACTLiGaO2 and LiAlO2 have similar lattice constants to GaN, and may prove useful as substrates for III-nitride epitaxy. We have found that these materials may be wet chemically etched in a number of acid solutions, including HF, at rates between 150–40,000 Å/min. Dry etching with SF6/Ar plasmas provides faster rates than Cl2/Ar or CH4/H2/Ar under Electron Cyclotron Resonance conditions, indicating the fluoride etch products are more volatile that their chloride or metalorganic/hydride counterparts. Dry etch rates are low ( < 2, 000 Å/min), providing high selectivity (>5) over the nitrides. The incorporation of hydrogen in these materials is also of interest because this could provide a reservoir of hydrogen that may passivate dopants in overlying nitride films. In 2H implanted samples, 50 % of the deuterium is lost by evolution from the surface by annealing at 400 °C for 20 min and all of the deuterium is gone at 700°C. The diffusivity of 2H is ∼10-13 cm2/s at 250°C in LiA1O2, approximately two orders of magnitude higher than in LiGaO2.

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