Reactive Ion Etching of WSi0.6 Gates for GaAs MESFETS

1986 ◽  
Vol 68 ◽  
Author(s):  
C. L. Lin ◽  
Peter D. Hoh

AbstractA process for reactive ion etching of 1μm and sub-micron WSi0.6 gates for GaAs MESFET integrated circuits has been developed.Using a CF4/O2 plasma, a 200am film of WSi0.6 could be etched in ≃ 5 minutes.This is sufficiently long for accurate process monitoring.A vertical edge profile has been obtained which is desirable for a self-aligned MESFET process.To achieve the vertical edge, careful control of the degree of over etch was necessary.This was accomplished by monitoring the intensity profile of a laser beam reflected from the wafer being etched.The widths of lines etched in WSi0.6 closely matched those of the resist pattern.Both 1μm and sub-micron FET's were fabricated.with excellent linewidth control and electrical characteristics

1990 ◽  
Vol 216 ◽  
Author(s):  
D.C. La Tulipe ◽  
D.J. Frank ◽  
H. Munekata

ABSTRACT-Although a variety of novel device proposals for GaSb/(Al,Ga)Sb/InAs heterostructures have been made, relatively little is known about processing these materials. We have studied the reactive ion etching characteristics of GaSb, (AI,Ga)Sb, and InAs in both methane/ hydrogen and chlorine gas chemistries. At conditions similar to those reported elsewhere for RIE of InP and GaAs in CH4/H2, the etch rate of (AI,Ga)Sb was found to be near zero, while GaSb and InAs etched at 200Å/minute. Under conditions where the etch mechanism is primarily physical sputtering, the three compounds etch at similar rates. Etching in Cl2 was found to yield anisotropic profiles, with the etch rate of (AI,Ga)Sb increasing with Al mole fraction, while InAs remains unetched. Damage to an InAs “stop layer” was investigated by sheet resistance and mobility measurements. These etching techniques were used to fabricate a novel InAs-channel FET composed of these materials. Several scanning electron micrographs of etching results are shown along with preliminary electrical characteristics.


1998 ◽  
Vol 27 (6) ◽  
pp. 661-667 ◽  
Author(s):  
C. A. Musca ◽  
J. F. Siliquini ◽  
E. P. G. Smith ◽  
J. M. Dell ◽  
L. Faraone

1988 ◽  
Vol 31 (11) ◽  
pp. 1647-1649
Author(s):  
D. Misra ◽  
C.R. Selvakumar ◽  
E.L. Heasell ◽  
D.J. Roulston

2002 ◽  
Vol 743 ◽  
Author(s):  
Marie Wintrebert-Fouquet ◽  
K. Scott ◽  
A. Butcher ◽  
Simon K H Lam

ABSTRACTWe present a comparative study of the effects of low power reactive ion etching (RIE) on GaN and InN. This new, highly chemical, dry etching, using CF4 and Ar, has been developed for thin nitride films grown at low temperature in our laboratories. GaN films were grown by remote plasma enhanced-laser induced chemical vapor deposition and InN films were grown by radio-frequency RF reactive sputtering. Commercial GaN samples were also examined. Optical and electrical characteristics of the films are reported before and after removing 100 to 200 nm of the film surface by RIE. We have previously shown that the GaN films, although polycrystalline after growth, may be re-crystallized below the growth temperature. Removal of the surface oxide has been found to be imperative since a polycrystalline residue remains on the surface after re-crystallization.


1989 ◽  
Vol 25 (2) ◽  
pp. 1239-1242 ◽  
Author(s):  
X.F. Meng ◽  
R.S. Amos ◽  
A.W. Lichtenberger ◽  
R.J. Mattauch ◽  
M.J. Feldman

1986 ◽  
Vol 76 ◽  
Author(s):  
D. Kirillov ◽  
C. B. Cooper ◽  
R. A. Powell

ABSTRACTReactive ion etching induced damage in GaAs and Al0.22Ga0.78As was studied using Raman spectroscopy. The phonon spectra of undoped materials allow evaluation of damage to the crystal lattice and the coupled plasmonphonon spectra of n-type material provide a sensitive probe of electrical characteristics. Studies were made of layers exposed to plasmas of Ar, SF6 and SiCl4. Conditions for low damage Ar plasma cleaning and for dielectric cap removal by SF6 were established. Etching in the SiCl4 plasma generally produced strong damage, although low damage etching was observed in a few cases.


1991 ◽  
Vol 240 ◽  
Author(s):  
C. P. Chen ◽  
K. S. Din ◽  
F. S. Huang

ABSTRACTIn the self-alignment technology for GaAs MESFET, the pattern technique for refractory suicide gate is needed. Reactive ion etching (RIE) of TaSix on GaAs has been performed in a mixture of CF4 and O2 Etching properties have been studied as function of oxygen percentage, total pressure and power. The samples were then examined in Scanning electron microscopy (SEM) and Auger electron spectroscopy (AES) to understand the surface morphology and constitution. It is found that the etch rate of TaSixincreased with increasing oxygen percentage initially, reached a maximum value near 10∼15% O2, then started to decrease with increasing oxygen at applied power 100 watt, pressure 50 mtorr, and total gas flow 40 seem. This etch rate also increases with RF power and total pressure in CF4 + O2 15% gas at gas flow rate 40 sccm. For GaAs etching, the rate is independent of oxygen percentage. This etch rate of GaAs also increases with power, but decreases with total pressure. Meanwhile, the SEM micrograph shows no undercut for sample after RIE at the applied power 140 watt with the pressure of 20 mtorr.


1991 ◽  
Vol 240 ◽  
Author(s):  
R. Pereira ◽  
M. Van Hove ◽  
W. De Raedt ◽  
C. Van Hoof ◽  
G. Borghs ◽  
...  

ABSTRACTThe damage introduced by CH4/H2 reactive ion etching (RIE) and its recovery after thermal annealing has been investigated by Hall measurements and low temperature photoluminescence (PL) on pseudomorphic AlGaAs/InGaAs modulation doped structures. After plasma exposure, the PL intensity has significantly decreased and shifted in energy. In order to study the recovery of the damage introduced by the plasma, thermal annealing was done at temperatures between 350 and 500°C. We observed that the luminescence emission is totally recovered after annealing at 450°C. Hall measurements at room temperature (RT) and at 77K showed that the electrical characteristics of these structures can be restored only after thermal annealing at 500°C.The optimised etching conditions have been applied in a fabrication process for submicron dry gate recessed pseudomorphic delta-doped AlGaAs/InGaAs modulation doped field effect transistors (MODFETs). For a 0.25 mm gatelength device the maximum DC transconductance value was as high as 680 mS/mm. The same value was extracted from measurements at 15 GHz.


1997 ◽  
Vol 487 ◽  
Author(s):  
C. A. Musca ◽  
E. P. G. Smith ◽  
J. F. Siliquini ◽  
J. M. Dell ◽  
J. Antoszewski ◽  
...  

AbstractMercury annealing of reactive ion etching (RIE) induced p- to n-type conversion in extrinsically doped p-type epitaxial layers of HgCdTe (x=0.31) has been used to reconvert n-type conversion sustained during RIE processing. For the RIE processing conditions used (400mT, CH4/H2, 90 W) p- to n-type conversion was observed using laser beam induced current (LBIC) measurements. After a sealed tube mercury anneal at 200°C for 17 hours, LBIC measurements clearly indicated no n-type converted region remained. Subsequent Hall measurements confirmed that the material consisted of a p-type layer, with electrical properties equivalent to that of the initial as-grown wafer (NA-ND=2× 1016 cm−3, μ=350 cm2.V−1.−1).


1997 ◽  
Vol 484 ◽  
Author(s):  
C. A. Musca ◽  
E. P. G. Smith ◽  
J. F. Siliquini ◽  
J. M. Dell ◽  
J. Antoszewski ◽  
...  

AbstractMercury annealing of reactive ion etching (RIE) induced p- to n-type conversion in extrinsically doped p-type epitaxial layers of HgCdTe (x=0.3 1) has been used to reconvert n-type conversion sustained during RIE processing. For the RIE processing conditions used (400mT, CH4/H2, 90 W) p- to n-type conversion was observed using laser beam induced current (LBIC) measurements. After a sealed tube mercury anneal at 200°C for 17 hours, LBIC measurements clearly indicated no n-type converted region remained. Subsequent Hall measurements confirmed that the material consisted of a p-type layer, with electrical properties equivalent to that of the initial as-grown wafer (NA-ND=2×1016 cm−3,.=350 cm2.V−1. S−1).


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