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.

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.

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.

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 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.

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.

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.

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.

Iodine-Based dry Etching Chemistries for InP and Related Compounds

1992 ◽  
Vol 282 ◽  
Author(s):  
S. J. Pearton ◽  
U. K. Chakrabarti ◽  
A. Katz ◽  
C. R. Abernathy ◽  
W. S. Hobson ◽  
...  
Keyword(s):  
Room Temperature ◽  
Dry Etching ◽  
Reaction Products ◽  
Ion Density ◽  
Sample Heating ◽  
Polymer Deposition ◽  
Etch Rates ◽  
Microwave Discharges ◽  
Related Compounds

ABSTRACTA comparison is given of the dry etching characteristics of InP and related materials in high ion density (>1011 cm−2 ) microwave discharges of HI, CH3I, C2H5I, C3H7I and C2H3I. The InIx species are more volatile than their InClx counterparts near room temperature and rapid etch rates can therefore be achieved without the need for sample heating. HI discharges provide faster etch rates than the halocarbon-based mixtures, but are more corrosive. All of these gas chemistries offer faster rates than conventional CH4/H2 mixtures. Halocarbon-iodide discharges still suffer from polymer deposition on the mask and within the reactor, as with CH4/H2. AES analysis shows an absence of contaminating residues with all of the iodine-based chemistries, and highly anisotropic features are obtained since the etching is driven by ion-enhanced desorption of the reaction products.

A Chemical Perspective of GaN Polarity: The use of Hydrogen Plasma Dry Etching Versus NaOH Wet Etching to Determine Polarity

2002 ◽  
Vol 722 ◽  
Author(s):  
Maria Losurdo ◽  
MariaMichela Giangregorio ◽  
Pio Capezzuto ◽  
Giovanni Bruno ◽  
Gon Namkoong ◽  
...  
Keyword(s):  
Surface Morphology ◽  
Plasma Etching ◽  
Hydrogen Plasma ◽  
Dry Etching ◽  
Surface Reactivity ◽  
Wet Etching ◽  
Hydrogen Treatment

AbstractThe use of dry hydrogen plasma etching is evaluated for determination of GaN polarity and critically compared to wet etching in NaOH. It is shown that hydrogen plasma etching is effective in revealing inversion domains (IDs) and some types of dislocations. This is because the surface morphology is unchanged by the hydrogen treatment, and, hence, the surface reactivity is not masked.

Plasma Chemistries for Dry Etching GaN, AIN, InGaN and InAIN

1996 ◽  
Vol 421 ◽  
Author(s):  
S. J. Pearton ◽  
C. B. Vartuli ◽  
J. W. Lee ◽  
S. M. Donovan ◽  
J. D. MacKenzie ◽  
...  
Keyword(s):  
Hydrogen Plasma ◽  
Critical Factor ◽  
Dry Etching ◽  
Ion Energies ◽  
Volatile Products ◽  
Etch Rates

AbstractEtch rates up to 7,000Å/min. for GaN are obtained in Cl2/H2/Ar or BCl3/Ar ECR discharges at 1–3mTorr and moderate dc biases. Typical rates with HI/H2 are about a factor of three lower under the same conditions, while CH4/H2 produces maximum rates of only ˜2000Å/min. The role of additives such as SF6, N2, H2 or Ar to the basic chlorine, bromine, iodine or methane-hydrogen plasma chemistries are discussed. Their effect can be either chemical ( in forming volatile products with N) or physical ( in breaking bonds or enhancing desorption of the etch products). The nitrides differ from conventional III-V's in that bondbreaking to allow formation of the etch products is a critical factor. Threshold ion energies for the onset of etching of GaN, InGaN and InAlN are ≥75eV.

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