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.

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.

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.

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.

A Comparison Between Dry Etching with an Electron Cyclotron Resonance Source and Reactive Ion Etching for GaAs and InP

1991 ◽  
Vol 240 ◽  
Author(s):  
S. W. Pang
Keyword(s):  
Cyclotron Resonance ◽  
Parallel Plate ◽  
Electron Cyclotron Resonance ◽  
Reactive Ion Etching ◽  
Electron Cyclotron ◽  
Gas Composition ◽  
Rf Power ◽  
Ion Etching ◽  
Plate System ◽  
Ecr Source

ABSTRACTEtching with an electron cyclotron resonance (ECR) source provides several advantages over conventional reactive ion etching (RIE). In this work, the results of GaAs and InP etching using a multipolar ECR source are presented and compared to RIE. The effects of microwave and rf power, gas composition, pressure, and source to sample distance on the etch characteristics of GaAs and InP were evaluated. Three different etch gases were used including CCl2F2, BCl3, and Cl2. The influence of microwave power on etch characteristics is compared to conventional parallel plate system using rf power alone.

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.

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