HI/H2 ECR Plasma Etching of III-V Semiconductors

1992 ◽  
Vol 268 ◽  
Author(s):  
S. J. Pearton ◽  
U. K. Chakrabarti ◽  
A. Katz ◽  
F. Ren ◽  
T. R. Fullowan ◽  
...  
Keyword(s):  
Plasma Etching ◽  
Electron Spectroscopy ◽  
Dry Etching ◽  
Hydrogen Passivation ◽  
Near Surface ◽  
Ecr Plasma ◽  
Order Of Magnitude ◽  
Polymer Deposition ◽  
Etch Rates ◽  
Surface Morphologies

ABSTRACTHI/H2/Ar discharges are shown to be universal etchants for rn-V semiconductors, giving rise to highly anisotropic features with smooth surface morphologies. At loy dc self bia:s (-100V) and low pressure (1 mTorr), etch rates for all III-V materials of >2000Å min−1 are possible for high HI percentages in the discharges, whereas rates greater than 1 Åm min−1 are obtained at higher pressures and dc biases. These etch rates are approximately an order of magnitude faster than for CH4/H2/Ar mixtures under the same conditions and there is no polymer deposition on the mask or within the reactor chamber with HI/H2/Ar. Auger Electron Spectroscopy reveals residue-free, stoichiometric surfaces after dry etching in this mixture. As i result, photoluminescence intensities from dry etched samples remain high with little apparent damage introduction. Changes in the near-surface carrier concentration due to hydrogen passivation effects are also negligible with HI-based mixtures in comparison to CH4-based dry etching.

Dry Etching Techniques and Chemistries for III-V Semiconductors

1990 ◽  
Vol 216 ◽  
Author(s):  
S. J. Pearton
Keyword(s):  
Plasma Etching ◽  
Cyclotron Resonance ◽  
Electron Cyclotron Resonance ◽  
Surface Damage ◽  
Dry Etching ◽  
Near Surface ◽  
Lattice Disorder ◽  
Ecr Plasma ◽  
Surface Morphologies

ABSTRACTDry etching of HI-V materials using both Cl-based (CCl2F2, SiCl4, BCl3, Cl2) and CH4/H2 discharges will be reviewed. The etch rates using chlorine-based mixtures are generally faster than those utilizing CH4/H2, but the latter gives smoother surface morphologies for In-containing compounds. The use of microwave (2.45 GHz) electron cyclotron resonance (ECR) discharges minimizes the depth of lattice disorder resulting from dry etching, relative to conventional RF (13.56 MHz) discharges. Recent results on the systematics of ECR plasma etching of both In- and Ga-based III-V semiconductors using CCl2F2/O2 and CH4/H2 mixtures will be discussed, including the determination of the maximum self-biases allowable which do not induce near-surface damage to the semiconductor. A further key issue is the prevention of changes in the surface stoichiometry of materials such as InP, where the lattice constituents may have considerably different volatilities in the particular discharge.

Dry Etching of InGaP and AlInP in CH4/H2/Ar

1996 ◽  
Vol 421 ◽  
Author(s):  
J. W. Lee ◽  
S. J. Pearton ◽  
C. J. Santana ◽  
E. S. Lambers ◽  
C. R. Abernathy ◽  
...  
Keyword(s):  
Plasma Etching ◽  
Cyclotron Resonance ◽  
Electron Cyclotron Resonance ◽  
Low Flow ◽  
Flow Rates ◽  
Ecr Plasma ◽  
Order Of Magnitude ◽  
Etch Stop ◽  
Etch Rates ◽  
Ecr Plasma Etching

AbstractElectron Cyclotron Resonance (ECR) plasma etching with additional if-biasing produces etch rates ≥ 2,500Å/min for InGaP and AlInP in CH4/H2/Ar. These rates are an order of magnitude or much higher than for reactive ion etching conditions (RIE) carried out in the same reactor. N2 addition to CH4/H2/Ar can enhance the InGaP etch rates at low flow rates, while at higher concentrations it provides an etch-stop reaction. The InGaP and AtlnP etched under ECR conditions have somewhat rougher morphologies and different stoichiometries up to ˜200Å from the surface relative to the RIE samples.

scholarly journals Dry Etching of III-V Nitrides

1995 ◽  
Vol 395 ◽  
Author(s):  
S. J. Pearton ◽  
R. J. Shul ◽  
G. F. McLane ◽  
C. Constantine
Keyword(s):  
Plasma Etching ◽  
Dry Etching ◽  
Ion Density ◽  
Chemical Inertness ◽  
Order Of Magnitude ◽  
High Bond ◽  
Bond Strengths ◽  
Dc Bias ◽  
Etch Rates

ABSTRACTThe chemical inertness and high bond strengths of the III-V nitrides lead to slower plasma etching rates than for more conventional III-V semiconductors under the same conditions. High ion density conditions (>3×1011cm−3) such as those obtained in ECR or magnetron reactors produce etch rates up to an order of magnitude higher than for RIE, where the ion densities are in the 109 cm−3 range. We have developed smooth anisotropic dry etches for GaN, InN, AlN and their alloys based on Cl2/CH4/H2/Ar, BCl3/Ar, Cl2/H2, C12/SF6, HBr/H2 and HI/H2 plasma chemistries achieving etch rates up to ∼4,000Å/min at moderate dc bias voltages (≤-150V). Ion-induced damage in the nitrides appears to be less apparent than in other III-V’s. One of the key remaining issues is the achievement of high selectivities for removal of one layer from another.

Comparison of Microwave ECR and RF Plasmas for Dry Etching of Single Crystal 6H-SiC

1994 ◽  
Vol 339 ◽  
Author(s):  
J. R. Flemish ◽  
K. Xie ◽  
W. Buchwald ◽  
L. Casas ◽  
J. H. Zhao ◽  
...  
Keyword(s):  
Single Crystal ◽  
Plasma Etching ◽  
Electron Cyclotron Resonance ◽  
Schottky Diodes ◽  
Substrate Bias ◽  
Rf Plasmas ◽  
Ecr Plasma ◽  
Current Voltage ◽  
Capacitance Voltage ◽  
Etch Rates

ABSTRACTElectron cyclotron resonance (ECR) plasma etching of single crystal 6H-SiC has been investigated using a CF4/O2 gas mixture and compared to conventional reactive ion etching (RIE) in a radio frequency (13.56 MHz) reactor. The use of ECR results in higher etch rates, lower levels of bias and smoother etched surfaces than rf-RIE. ECR etch rates exceeding 100 nm/min have been obtained at a substrate bias of-100 V. Etch rate and surface morphology have been studied as a function of pressure, bias and power. Auger electron spectroscopy shows that ECR etching leaves no residues unlike rf-RIE which leaves residues containing Al, F, O and C. The current-voltage and capacitance-voltage measurements of Schottky diodes show that there is far less damage induced by ECR etching compared to rf-RIE.

scholarly journals ICP Dry Etching of III-V Nitrides

1997 ◽  
Vol 468 ◽  
Author(s):  
C. B. Vartuli ◽  
J. W. Lee ◽  
J. D. MacKenzie ◽  
S. M. Donovan ◽  
C. R. Abernathy ◽  
...  
Keyword(s):  
Plasma Etching ◽  
Inductively Coupled Plasma ◽  
Dry Etching ◽  
Rf Power ◽  
Inductively Coupled Plasma Etching ◽  
Inductively Coupled ◽  
Dc Bias ◽  
Etch Rates ◽  
Icp Dry Etching

ABSTRACTInductively coupled plasma etching of GaN, AlN, InN, InGaN and InAlN was investigated in CH4/H2/Ar plasmas as a function of dc bias, and ICP power. The etch rates were generally quite low, as is common for III-nitrides in CH4 based chemistries. The etch rates increased with increasing dc bias. At low rf power (150W), the etch rates increased with increasing ICP power, while at 350W rf power, a peak was found between 500 and 750 W ICP power. The etched surfaces were found to be smooth, while selectivities of etch were ≤ 6 for InN over GaN, AlN, InGaN and InAlN under all conditions.

High Density Dry Etching of (Ba,Sr)TiO3 and LaNiO3

1999 ◽  
Vol 596 ◽  
Author(s):  
K. P. Lee ◽  
K. B. Jung ◽  
A Srivastava ◽  
D. Kumar ◽  
R. K. Singh ◽  
...  
Keyword(s):  
Thin Films ◽  
Plasma Etching ◽  
Single Layer ◽  
Dry Etching ◽  
High Density ◽  
Pattern Transfer ◽  
Removal Rates ◽  
Etch Rates ◽  
Density Plasma ◽  
Maximum Removal

AbstractHigh density plasma etching of (Ba,Sr)TiO3 (BST) and LaNiO3 (LNO) thin films was performed in two different plasma chemistries, Cl2/Ar and CH4/H2/Ar. While the latter chemistry produced extremely low etch rates (≤ 100 Å-min−1) under all conditions, the Cl2/Ar produced a smooth anisotropic pattern transfer. The etching was still strongly ion-assisted, but maximum removal rates of ∼900 Å min−1 for both materials were achieved with selectivities of ∼16 for BST and ∼7 for LNO over Si. A single layer of thick (∼7 μm) photoresist is an effective mask under these conditions.

Patterning of GaN in High-Density Cl2- and BCl3-Based Plasmas

1997 ◽  
Vol 468 ◽  
Author(s):  
R. J. Shul ◽  
R. D. Briggs ◽  
J. Han ◽  
S. J. Pearton ◽  
J. W. Lee ◽  
...  
Keyword(s):  
Plasma Etching ◽  
Chemical Nature ◽  
Photonic Devices ◽  
High Density ◽  
Low Degree ◽  
Patterning Technique ◽  
High Bond ◽  
Dc Bias ◽  
Etch Rates ◽  
Surface Morphologies

ABSTRACTFabrication of group-Ill nitride electronic and photonic devices relies heavily on the ability to pattern features with anisotropie profiles, smooth surface morphologies, etch rates often exceeding 0.5 μm/min, and a low degree of plasma-induced damage. Patterning these materials has been especially difficult due to their high bond energies and their relatively inert chemical nature as compared to other compound semiconductors. However, high-density plasma etching has been an effective patterning technique due to ion fluxes which are 2 to 4 orders of magnitude higher than conventional RIE systems. GaN etch rates as high as -1.3 μm/min have been reported in ECR generated ICI plasmas at -150 V dc-bias. In this study, we report high-density GaN etch results for ECR- and ICP-generated plasmas as a function of Cl2- and BCl3-based plasma chemistries.

Dry and Wet Etch Processes for NiMnSb, LaCaMnO3 and Related Materials

1997 ◽  
Vol 494 ◽  
Author(s):  
J. Hong ◽  
J. J. Wang ◽  
E. S. Lambers ◽  
J. A. Caballero ◽  
J. R. Childress ◽  
...  
Keyword(s):  
Plasma Etching ◽  
Smooth Surface ◽  
Dielectric Materials ◽  
Ion Density ◽  
Ion Energy ◽  
Sensor Devices ◽  
Etch Rates ◽  
Surface Morphologies ◽  
Wet Etch ◽  
Dry Etch

ABSTRACTA variety of plasma etching chemistries were examined for patterning NiMnSb Heusler thin films and associated A12O3 barrier layers. Chemistries based on SF6 and Cl2 were all found to provide faster etch rates than pure Ar sputtering. In all cases the etch rates were strongly dependent on both the ion flux and ion energy. Selectivities of ≥20 for NiMnSb over A12O3 were obtained in SF6-based discharges, while selectivities ≤5 were typical in Cl2 and CH4/H2 plasma chemistries. Wet etch solutions of HF/H2O and HNO3/H2SO4/H2O were found to provide reaction-limited etching of NiMnSb that was either non-selective or selective, respectively, to A12O3. In addition we have developed dry etch processes based on Cl2/Ar at high ion densities for patterning of LaCaMnO3 (and SmCo permanent magnet biasing films) for magnetic sensor devices. Highly anisotropie features are produced in both materials, with smooth surface morphologies. In all cases, SiO2 or other dielectric materials must be used for masking since photoresist does not retain its geometrical integrity upon exposure to the high ion density plasma.

CH4 :H2 :Ar rf/ECR Plasma Etching of GaAs and InP

1991 ◽  
Vol 223 ◽  
Author(s):  
Victor. J. Law ◽  
S. G. Ingram ◽  
G. A. C. Jones ◽  
R. C. Grimwood ◽  
H. Royal
Keyword(s):  
Plasma Etching ◽  
Gas Flow ◽  
Electron Cyclotron Resonance ◽  
Kinetic Studies ◽  
High Electron Mobility Transistor ◽  
Rf Plasma ◽  
High Electron ◽  
Ecr Plasma ◽  
Etch Rates ◽  
Ecr Plasma Etching

ABSTRACTA comparative study of CH4 :H2 , and CH4 :H2 :Ar rf-plasma and microwave electron cyclotron resonance (ECR) plasma etching of GaAs and InP is presented. The study is in two parts;(i) Kinetic studies of GaAs and InP etch rates as a function of the constituent gas flow rates, applied rf and microwave powers, substrate temperature and position. The results indicate that CH4 :H2 :Ar ECR etching of GaAs is 10× more efficient in the utilisation of the CH4 precursor gas than rf-plasmas. However, the absolute etch rates are lower (70 nm min−1 for rf and 25 nm min−1 for rf biassed ECR-plasmas).The effect of etching conditions on InP morphology is also examined.(ii) The study of electrical “damage” in GaAs/AlGaAs high electron mobility transistor (HEMT) Hall bar structures, was investigated by ECR-plasma etching off the top GaAs capping layer. Results indicate that ECR-plasma etching with an rf-bias between 0V and −30V does not significantly effect the electrical characteristics of such devices at 300K, with some degredation at 1.2 K.

High Density Plasma Etching of Ta2O5-Selectivity to Si and Effect of UV Light Enhancement

1999 ◽  
Vol 606 ◽  
Author(s):  
K.P Lee ◽  
H. Cho ◽  
R. K. Singh ◽  
S. J. Pearton ◽  
C. Hobbs ◽  
...  
Keyword(s):  
Plasma Etching ◽  
Inductively Coupled Plasma ◽  
Uv Light ◽  
Inductively Coupled ◽  
Uv Illumination ◽  
Icp Etching ◽  
Light Enhancement ◽  
Order Of Magnitude ◽  
Etch Rates ◽  
Post Deposition

AbstractEtch rates up to 1200 Åmin−1 for Ta2O5 were achieved in both SF6/Ar and Cl2/Ar discharges under Inductively Coupled Plasma conditions. The etch rates with N2/Ar or CH4/H2/Ar chemistries were an order of magnitude lower. There was no effect of post deposition annealing on the Ta2O5 etch rates, at least up to 800 °C. Selectivities to Si of ∼1 were achieved at low source powers, but at higher powers the Si typically etched 4-7 times faster than Ta 20 5. UV illumination during ICP etching in both SF6/Ar and Cl2/Ar produced significant enhancements (up to a factor of 2) in etch rates due to photo-assisted desorption of the TaFx products. The UV illumination is an alternative to employing elevated sample temperatures during etching to increase the volatility of the etch products and may find application where the thermal budget should be minimized during processing.

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