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.

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.

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 236 ◽  
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 rf 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, then 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.

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.

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.

scholarly journals Compact Two-Section Half-Wave Balun Based on Planar Artificial Transmission Lines

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Changjun Liu ◽  
Zhenyu Yin ◽  
Yilan Yang ◽  
Wen Huang
Keyword(s):  
Transmission Line ◽  
Transmission Lines ◽  
Microwave Power ◽  
Parallel Plate ◽  
Return Loss ◽  
Characteristic Impedance ◽  
Size Reduction ◽  
Power Combining ◽  
Half Wave ◽  
Phase Balance

Artificial transmission lines are realized by a series of meandered-line inductors, parallel-plate capacitors, and interdigital capacitors, which belong to metamaterial transmission lines. An ameliorated artificial transmission line is proposed to realize a low characteristic impedance transmission line. A two-section half-wave balun at 900 MHz is designed, fabricated, and measured in this paper. The compact balun is based on conventional and ameliorated planar artificial transmission lines instead of microstrip transmission lines. The main advantage of the proposed balun is its size reduction, which occupies only about 10% of a conventional one. Measured results match well with theory and simulation. The balun features excellent amplitude and phase balance in microwave power combining and a reasonable bandwidth of the return loss as well.

Inductively Coupled Plasma Etching of Pt/Ti Electrodes in Cl-Based Plasma

2013 ◽  
Vol 721 ◽  
pp. 346-349
Author(s):  
Zhi Qin Zhong ◽  
Cheng Tao Yang ◽  
Guo Jun Zhang ◽  
Shu Ya Wang ◽  
Li Ping Dai
Keyword(s):  
Process Parameters ◽  
Plasma Etching ◽  
Inductively Coupled Plasma ◽  
Etch Rate ◽  
Dry Etching ◽  
Rf Power ◽  
Inductively Coupled Plasma Etching ◽  
Inductively Coupled ◽  
High Etch Rate ◽  
Ar Gas

Dry etching of Pt/Ti film was carried out using Cl2/Ar plasmas in an inductively coupled plasma (ICP) reactor. The influence of the various process parameters, such as RIE power, ICP power and Cl2/Ar gas mixing ratio, on the etch rate and selectivity of photoresist to Pt/Ti film were investigated systematically and optimized. It was revealed that the etch rate and the selectivity strongly depended on the key process parameters. The etch rate was found to increase dramatically with increasing of RIE power and ICP power. But by changing the ratio of Cl2 to the total gas, the maximum etch rate could be obtained at the proper ratio of 20%. The results also indicated too low or too high RIE power and the Cl2 ratio was detrimental to the selectivity. The optimized parameters of Pt/Ti dry etching for high etch rate and low selectivity of photoresist to Pt/Ti were obtained to be pressure: 10mT, RF power: 250W, ICP power: 0W, Cl2: 8sccm (standard cubic centimeters per minute), Ar: 32sccm.

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.

Composite right/left-handed transmission line with array of thermocouples for generating terahertz radiation

2020 ◽  
Vol 92 (2) ◽  
pp. 20502
Author(s):  
Behrokh Beiranvand ◽  
Alexander S. Sobolev ◽  
Anton V. Kudryashov
Keyword(s):  
Transmission Line ◽  
Terahertz Radiation ◽  
Transmission Lines ◽  
Software Package ◽  
Optical Pulses ◽  
Capacitively Coupled ◽  
Voltage Difference ◽  
Left Handed ◽  
Microwave Transmission ◽  
Commercial Software Package

We present a new concept of the thermoelectric structure that generates microwave and terahertz signals when illuminated by femtosecond optical pulses. The structure consists of a series array of capacitively coupled thermocouples. The array acts as a hybrid type microwave transmission line with anomalous dispersion and phase velocity higher than the velocity of light. This allows for adding up the responces from all the thermocouples in phase. The array is easily integrable with microstrip transmission lines. Dispersion curves obtained from both the lumped network scheme and numerical simulations are presented. The connection of the thermocouples is a composite right/left-handed transmission line, which can receive terahertz radiation from the transmission line ports. The radiation of the photon to the surface of the thermocouple structure causes a voltage difference with the bandwidth of terahertz. We examined a lossy composite right/left-handed transmission line to extract the circuit elements. The calculated properties of the design are extracted by employing commercial software package CST STUDIO SUITE.

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