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.

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.

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.

Spectroscopy of Ecr Plasma Used for Depositing Amorphous and Microcrystalline Silicon Films

2002 ◽  
Vol 715 ◽  
Author(s):  
Marsela Pontoh ◽  
Vikram L. Dalal ◽  
Neha Gandhi
Keyword(s):  
Electron Cyclotron Resonance ◽  
Optical Emission ◽  
Surprising Result ◽  
Ion Density ◽  
Ecr Plasma ◽  
The Standard Model ◽  
Langmuir Probe Measurements ◽  
Si Films ◽  
Mass Spectrometery ◽  
Probe Measurements

AbstractElectron-cyclotron-resonance (ECR) plasma are used extensively to deposit amorphous and microcrystalline Si and (Si,Ge) films, and for depositing oxides and nitrides of Si. In this paper, we discuss the results of optical emission spectroscopy, Langmuir probe measurements and mass-spectrometery measurements of the ECR plasma when used to deposit a-Si films. We study He and H diluted plasmas. We find that the addition of hydrogen to the gas mixture immediately reduces the flux of the active (e.g. SiH, SiH2,SiH3) radicals and ions that are responsible for the growth of films. Thus, introducing hydrogen in the mixture reduces the growth rate significantly, not only because it etches the film during growth, but primarily because it reduces the production of the needed growth radicals. We find an excellent correlation between growth rates and SiH intensity signal. A surprising result is that the densities of all three ions, SiH, SiH2 and SiH3, arriving at the substrate are comparable in magnitude in this low pressure reactor, with the SiH ion density becoming larger than the SiH3 density at higher powers. This observation raises some doubt about the standard model for growth that states that SiH3 is the dominant radical responsible for growth during plasma CVD processes. We also find that decreasing the pressure increases the ratio of H/H2 arriving at the substrate, which in turn means that more H ions and atoms are available to do etching of the growing film and change its properties at lower pressures.

Comments on the Langmuir probe measurements of radio-frequency capacitive argon–hydrogen mixture discharge at low pressure

2018 ◽  
Vol 96 (5) ◽  
pp. 494-500 ◽  
Author(s):  
Murat Tanışlı ◽  
Nesli̇han Şahi̇n ◽  
Süleyman Demi̇r
Keyword(s):  
Radio Frequency ◽  
Electron Density ◽  
Langmuir Probe ◽  
Low Pressure ◽  
Hydrogen Gas ◽  
Floating Potential ◽  
Rf Power ◽  
Measurement Results ◽  
Langmuir Probe Measurements ◽  
Probe Measurements

In this paper, the current–voltage graphs of discharge in the chamber of capacitive coupled radio frequency (CCRF) at low pressure were presented for Langmuir probe. The Langmuir probe measurements for estimating the electron density and temperature in capacitive coupled discharges at low pressures were presented and the electron temperatures of the Ar–H2 mixture discharge generated at different conditions were reported using the Langmuir probe. The focus of this study is that the CCRF discharge can be determined and explained using the characteristics of plasma by means of Langmuir probe measurements for the different hydrogen rates in Ar–H2 mixture discharge. The measurement results of Langmuir probe gave values around 1015 m−3 for the electron density. The floating potential depended on the electronegative gas amount. It was found that the increase of hydrogen gas amount in the mixture discharge caused the decrease of the floating potential. Also, a decrease in the argon (Ar) metastable with the increase in hydrogen (H2) content was obtained. When the applied radio frequency (RF) power was increased, the thickness and collisionless sheath occurring at lower RF power could transform to thin sheath.

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.

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.

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