Cl2-Based ECR Etching of InGaP, AlInP and AIGaP

1996 ◽  
Vol 421 ◽  
Author(s):  
J. Hong ◽  
J. W. Lee ◽  
S. J. Pearton ◽  
C. Santana ◽  
C. R. Abernathy ◽  
...  
Keyword(s):  
Microwave Power ◽  
Etch Rate ◽  
Electron Cyclotron Resonance ◽  
High Rate ◽  
Chamber Pressure ◽  
Rf Power ◽  
Polymer Addition ◽  
Ar Plasma ◽  
Etch Rates ◽  
Etched Surface

AbstractHigh microwave power (1000W) Electron Cyclotron Resonance (ECR) Cl2/Ar plasma produce etch rates for In0.5Ga0.5P, Al0.5In0.5P and Al0.5Ga0.5P of ˜1um/min. at low pressure (1.5mTorr), moderate rf power levels (150W) and room temperature. Addition of Cl2 into Ar makes much smoother etched surface morphology as well as increasing the etch rate. All parameters, including microwave power, chamber pressure and rf power increase the etch rate of these alloys. Especially, there is at least a minimum rf power in order to get much higher etch rate with increasing microwave power. AlGaP in Cl2/Ar discharges has lower etch rates than InGaP or AlInP, which is similar to the results based on CH4/H2/Ar plasma chemistries. The Cl2/Ar chemistry enables smooth, high-rate etching without the need for polymer addition and thus simplifies the processing.

High Rate Dry Etching of GaN, AIN and InN in ECR Cl2/CH4/H2/Ar Plasmas

1995 ◽  
Vol 380 ◽  
Author(s):  
C. B. Vartuli ◽  
S. J. Pearton ◽  
C. R. Abernathy ◽  
R. J. Shul ◽  
S. P. Kilcoyne ◽  
...  
Keyword(s):  
Surface Morphology ◽  
Microwave Power ◽  
Etch Rate ◽  
Surface Composition ◽  
Plasma Chemistry ◽  
High Rate ◽  
Rf Power ◽  
Plasma Parameters ◽  
Wide Range ◽  
Etch Rates

ABSTRACTEtch rates for binary nitrides in ECR Cl2/CH4/H2/Ar are reported as a function of temperature, rf-bias, microwave power, pressure and relative gas proportions. GaN etch rates remain relatively constant from 30 to 125 °C and then increase to a maximum of 2340 Å-min−1 at 170 °C. The AIN etch rate decreases throughout the temperature range studied with a maximum of 960 Å-min−1 at 30 °C. When CH4 is removed from the plasma chemistry, the GaN and InN etch rates are slightly lower, with less dramatic changes with temperature. The surface composition of the III–V nitrides remains unchanged over the temperatures studied. The GaN and InN rates increase significantly with rf power, and the fastest rates for all three binaries are obtained at 2 mTorr. Surface morphology is smooth for GaN over a wide range of conditions, whereas InN surfaces are more sensitive to plasma parameters.

In-Situ Fiberoptic Thermometry Measurements Of Wafer Temperature During Plasma Etching Using An Electron Cyclotron Resonance Source

1995 ◽  
Vol 406 ◽  
Author(s):  
S. Thomas ◽  
E. W. Berg ◽  
S. W. Pang
Keyword(s):  
Microwave Power ◽  
Cyclotron Resonance ◽  
Etch Rate ◽  
Electron Cyclotron Resonance ◽  
Plasma Heating ◽  
Electron Cyclotron ◽  
Chamber Pressure ◽  
Rf Power ◽  
Wafer Temperature

AbstractThe increase in wafer temperature due to plasma heating during etching has been studied. Si and InP were etched using a high ion density discharge generated by an electron cyclotron resonance source. The wafer temperature was measured in-situ using fiberoptic thermometry as microwave power, rf power, chamber pressure, and gas flow were varied. Wafer temperatures increased with both microwave and rf power, and decreased with chamber pressure. For rf power of 50 W, chamber pressure of 1 mTorr, a source distance of 13 cm, and 10 sccm Ar flow, an increase in microwave power from 50 to 500 W caused the temperature to increase from 62 to 186 °C. Additionally, the use of He flowing at the backside of the wafer for temperature control was analyzed. By setting the backside He pressure at 3 Torr, the temperature increased from 20 °C at the beginning of the etch to only 29 °C after 12 min. Time dependent etch characteristics of InP were studied and related to the wafer temperature measurements. At 100 W microwave power, the InP etch rate increased from 100 to 400 nm/min as the wafer temperature rose from 20 to 150 °C. As the temperature increased above 150 °C, the profile became more undercut and the surface morphology improved. By setting the stage temperature to -100 °C and using 3 Torr He pressure at the backside of the wafer, the InP etch rate remained constant during etching and undercutting was suppressed. For 500 W microwave power, a fast InP etch rate of 2 μm/min was obtained when the wafer temperature was <110 °C, and it increased to over 4 μm/min when the temperature was >150 °C.

Relating Photoresist Etch Characteristics to Langmuir Probe Measurements in an Electron Cyclotron Resonance Source

1993 ◽  
Vol 324 ◽  
Author(s):  
K. T. Sung ◽  
W. H. Juan ◽  
S. W. Pang ◽  
M. Dahimene
Keyword(s):  
Microwave Power ◽  
Langmuir Probe ◽  
Cyclotron Resonance ◽  
Etch Rate ◽  
Electron Cyclotron Resonance ◽  
Rf Power ◽  
Ion Density ◽  
Source Distance ◽  
Langmuir Probe Measurements ◽  
Probe Measurements

AbstractIn this work, Langmuir probe measurements were used to characterize a multipolar electron cyclotron resonance (ECR) plasma source. This system has many controllable parameters including microwave power, rf power, gas, pressure, flow rate, and source distance. Both double and triple Langmuir probes were used for the plasma characterization. The results from the Langmuir probe measurements were correlated to the etch characteristics of photoresist. Ion density and photoresist etch rate were found to increase with microwave power but decrease with source distance. However, rf power does not have significant influence on ion density although the photoresist etch rate increases substantially with if power. Ion density first increases then decreases at higher pressure. Maximum ion density occurs at lower pressure for larger distance below the ECR source. Ion density uniformity for an O2 plasma is ±2% across a 16 cm diameter region at 23 cm below the source. For photoresist etched at 10 cm source distance, etch rate uniformity is ±2% for a 15 cm diameter wafer. The results from the Langmuir probe measurements indicate that photoresist etching is enhanced by ion density and ion energy.

Low Temperature Silicon Oxidation With Electron Cyclotron Resonance Oxygen Plasma

1991 ◽  
Vol 235 ◽  
Author(s):  
K. T. Sung ◽  
S. W. Pang
Keyword(s):  
Low Temperature ◽  
Microwave Power ◽  
Cyclotron Resonance ◽  
Oxygen Plasma ◽  
Permanent Magnets ◽  
Electron Cyclotron Resonance ◽  
Electron Cyclotron ◽  
Rf Power ◽  
Source Distance ◽  
Ecr Source

ABSTRACTSilicon was oxidized at low temperature with an oxygen plasma generated by an electron cyclotron resonance (ECR) source. The ECR source utilized a multicusp magnetic field formed by permanent magnets. Microwave power at 2.45 GHz was applied to the source and if power at 13.56 MHz was applied to the sample stage. Si oxidation was studied as a function of source distance, pressure, microwave power, and rf power. The oxide thickness increases with microwave and rf power but decreases with source distance. The oxidation rate increases with pressure up to 12 mTorr, men decreases at higher pressure. The relative emission intensities in the plasma monitored using optical emission spectroscopy showed similar dependence on the source distance and microwave power. Oxidation temperature was estimated to be <100°C. Using ellipsometry and X-ray photoelectron spectroscopy, the oxidized films were found to be close to that of thermal oxide with refractive index at 1.45 and oxygen to silicon ratio of 2. From the current-voltage and capacitance-voltage measurements, the breakdown fields of these oxide films were 6.3 MV/cm and the fixed charge densities were 7×1010 cm−2.

Comparison of ICl and IBr for Dry Etching of III-Nitrides

1996 ◽  
Vol 449 ◽  
Author(s):  
C. B. Vartuli ◽  
J. W. Lee ◽  
J. D. MacKenzie ◽  
S. J. Pearton ◽  
C. R. Abernathy ◽  
...  
Keyword(s):  
Silicon Nitride ◽  
Silicon Dioxide ◽  
Microwave Power ◽  
Etch Rate ◽  
Product Formation ◽  
Bond Breaking ◽  
Weakly Bound ◽  
Preferential Loss ◽  
Etch Rates ◽  
Dry Etch

ABSTRACTICl/Ar ECR discharges provide the fastest dry etch rates reported for GaN, 1.3 µm/min. These rates are much higher than with Cl2/Ar, CH4/H2/Ar or other plasma chemistries. InN etch rates up to 1.15 µm/min and 0.7 µm/min for In0.5Ga0.5N are obtained, with selectivities up to 5 with no preferential loss of N at low rf powers and no significant residues remaining. The rates are much lower with IBr/Ar, ranging from 0.15 µm/min for GaN to 0.3 µm/min for InN. There is little dependence on microwave power for either chemistry because of the weakly bound nature of IC1 and IBr. In all cases the etch rates are limited by the initial bond breaking that must precede etch product formation and there is a good correlation between materials bond energy and etch rate. The fact that low microwave power can be employed is beneficial from the viewpoint that photoresist masks are stable under these conditions, and there is no need for use of silicon nitride or silicon dioxide. Selectivities for GaN over A1N with IC1 and IBr are still lower than with Cl2- only.

Reactive ion Etching of PbZrxTi1−xO3 and Ruo2 Tein Films

1993 ◽  
Vol 310 ◽  
Author(s):  
Dilip P. Vijay ◽  
Seshu B. Desu ◽  
Wei Pan
Keyword(s):  
Thin Films ◽  
Solid Solution ◽  
Etch Rate ◽  
Reactive Ion Etching ◽  
Gas Pressure ◽  
Limiting Factor ◽  
Rf Power ◽  
Ion Etching ◽  
Pzt Thin Films ◽  
Etch Rates

AbstractIn this work, we have identified a suitable etch gas (CCI2,F2 ) for Reactive Ion Etching (RIE) of PZT thin films on RuO2 electrodes. The etch rate and anisotropy have been studied as a function of etching conditions. The effect of gas pressure, RF power and O2 concentration on the etch rate have been determined. It was found that ion bombardment effects are primarily responsible for the etching of both PZT and RuO2 thin films. Etch rates of the order of 20-30 nm/min were obtained for PZT thin films under low gas pressure and high RF power conditions. The etch residues and the relative etch rates of the components of the PZT solid solution were determined using XPS. The results show that the etching of PbO is the limiting factor in the etch process. For RuO2 thin films, etch rates of the order of 8-10 nm/min were obtained when O2 was added to the etch gas.

Silicon Electromachining Processes in Aqueous Solutions

1998 ◽  
Vol 546 ◽  
Author(s):  
M. Kovler ◽  
D. Starosvetsky ◽  
Y. Nemirovsky ◽  
J. Yahalom
Keyword(s):  
Aqueous Solutions ◽  
Etch Rate ◽  
Cathodic Polarization ◽  
High Rate ◽  
Alkaline Solutions ◽  
Potential Range ◽  
Etched Surface

AbstractHigh rate of etching of silicon was obtained by non conventional cathodic polarization in alkaline solutions. When the process was carried out at potentials more negative than −10 V it caused electropolishing of the etched surface. Shifting the potential in the cathodic direction increases the etch-rate parabolically and enhances the effect of polishing. The etch-rate increased by more than two orders of magnitude over the potential range from −10 to −40 V, and reached the value of about 250 micron/hour at 60 °C. Additionally, the etch-rate of n-Si was found to be markedly enhanced by illumination.

Evaluation of Dry Etching Induced Damage of Gainas Using Transmission Lines and Schottky Diodes

1993 ◽  
Vol 324 ◽  
Author(s):  
S. Thomas ◽  
S. W. Pang
Keyword(s):  
Transmission Line ◽  
Transmission Lines ◽  
Microwave Power ◽  
Etch Rate ◽  
Schottky Diodes ◽  
Dry Etching ◽  
Rf Power ◽  
Ion Energy ◽  
Source Distance ◽  
Ecr Source

AbstractPlasma etching of GaInAs and AlInAs has been carried out in a system which consists of an electron cyclotron resonance (ECR) source and an rf-powered stage. Since the ECR source can generate a plasma with low ion energy, dry etching induced damage is expected to be minimal. In this study, Schottky diodes and transmission lines were fabricated on the etched GaInAs surface. The diode and transmission line characteristics were evaluated as a function of etch conditions. For the etching of GaInAs and AllnAs, C12 and Ar were used as the etch gases. In addition to the ratio of the two gases, microwave power, rf power, pressure, and source distance were varied and their effects on etch rate, morphology, and surface damage were analyzed. Etch rate increased monotonically with microwave power, rf power, and C12 percentage. Etch rate decreased with increasing distance and reached a maximum for a pressure of 1 mTorr. The etch conditions for the damage study were chosen to maintain smooth morphology. One of the most important factors influencing damage was the ion energy which can be limited by using low rf power and short source distance. Minimum damage was obtained at 1 mTorr which provides the optimal balance between high etch rate and low ion energy. Besides limiting ion energy, the addition of Cl2 reduced etch-induced damage. The specific contact resistivity and sheet resistivity obtained from transmission line measurements of dryetched n-GaInAs were lower than the wet-etched samples. Schottky diode analysis show reduction in barrier height and breakdown voltage after Ar sputtering. Addition of 10% C12 is sufficient for full recovery of the diode characteristics.

Photoreflectance Characterization of Etch-Induced Damage in Dry Etched GaAs

1993 ◽  
Vol 324 ◽  
Author(s):  
O.J. Glembocki ◽  
J.A. Tuchman ◽  
K.K. Ko ◽  
S.W. Pang ◽  
A. Giordana ◽  
...  
Keyword(s):  
Fermi Level ◽  
Valence Band ◽  
Microwave Power ◽  
Cyclotron Resonance ◽  
Electron Cyclotron Resonance ◽  
Electron Cyclotron ◽  
Rf Power ◽  
Level Shifts ◽  
Ecr Source

AbstractPhotoreflectance has been used to characterize the etch-induced damage in GaAs processed in an Ar/Cl2 plasma generated by an electron-cyclotron resonance (ECR) source. We show that the damage is localized to the surface and that it is most influenced by the RF power, with little effect from the microwave power. The Fermi-level is observed to be unchanged in n-GaAs and remains near midgap, while for p-GaAs, the Fermi level shifts from near the valence band to midgap. Etch-induced anisite defects are proposed as a possible source of the damage.

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