Comparison Of F2 Plasma Chemistries For Deep Etching Of SiC

2000 ◽  
Vol 640 ◽  
Author(s):  
K. P. Lee ◽  
P. Leerungnawarat ◽  
S. J. Pearton ◽  
F. Ren ◽  
S. N. G. Chu ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Etch Rate ◽  
Low Cost ◽  
Surface Region ◽  
High Rate ◽  
Near Surface ◽  
Ion Energy ◽  
Deep Etching ◽  
Process Pressure ◽  
Via Holes

ABSTRACTA number of F2-based plasma chemistries (NF3, SF6, PF5 and BF3) were investigated for high rate etching of SiC. The most advantageous of these is SF6, based on the high rate (0.6 μm · min−1) it achieves and its relatively low cost compared to NF3. The changes in electrical properties of the near-surface region are relatively minor when the incident ion energy is kept below approximately 75 eV. At a process pressure of 5 mTorr, the SiC etch rate falls-off by ∼15 % in 30 μm diameter via holes compared to larger diameter holes (> 60 μm diameter) or open areas on the mask.

Doping Effects on the Etching Chemistry of GaAs and Si

1990 ◽  
Vol 204 ◽  
Author(s):  
F. A. Houle
Keyword(s):  
Etch Rate ◽  
Driving Forces ◽  
Surface Region ◽  
Near Surface ◽  
Doping Effects ◽  
Independent Mechanism ◽  
Semiconductor Etching ◽  
Surface Intermediates ◽  
Microscopic Picture ◽  
P Type

ABSTRACTDoping effects on semiconductor etching rates have been proposed to be associated with field effects in the near-surface region. Detailed investigations of the chemistry of nand p-type Si and GaAs indicate that the majority carrier can also play an important role in determining the reactivity of surface intermediates, providing an independent mechanism for influencing the etch rate. A microscopic picture of central driving forces in semiconductor etching deduced from the doping cffects is proposed.

scholarly journals Influence of Negative Charging on High Rate SiC Etching for GaN HEMT MMICs

2010 ◽  
Vol 645-648 ◽  
pp. 791-794 ◽  
Author(s):  
Naoya Okamoto ◽  
Kenji Imanishi ◽  
Toshihide Kikkawa ◽  
Naoki Nara
Keyword(s):  
Etch Rate ◽  
High Rate ◽  
Gan Hemt ◽  
Icp Etching ◽  
Via Holes ◽  
Etching Profile ◽  
Etching Behavior ◽  
Differential Etching ◽  
The Difference

We discuss the influence of negative charging on high-rate ICP etching of SiC via-holes for GaN HEMT MMICs. There is large differential etching behavior such as etch rate, etching profile, and RIE lag between S.I.- and n-SiC substrates because of the difference in wafer heating and negative charging of the sidewall during etching between both substrates. We analyze the difference in negative charging between both substrates by simulating the etching profile.

Influence of Low-Temperature Argon Ion-Beam Treatment on the Photovoltage Spectra of Standard Cz Si Wafers

2007 ◽  
Vol 131-133 ◽  
pp. 333-338 ◽  
Author(s):  
Anis M. Saad ◽  
Olga V. Zinchuk ◽  
N.A. Drozdov ◽  
A.K. Fedotov ◽  
A.V. Mazanik
Keyword(s):  
Low Temperature ◽  
Spectral Region ◽  
Ion Beam ◽  
Surface Region ◽  
Near Surface ◽  
Ion Energy ◽  
Ion Beam Treatment ◽  
P Type ◽  
20 Nm ◽  
Argon Ion

The main goal of this work is to investigate the influence of low-temperature argon ionbeam treatment on the electric and structural properties of a near-surface region of the standard commercial p-type Cz Si wafers, and to compare the effects of Ar+ and H+ ion-beam treatment. The measurements of thermo-EMF have shown that both Ar+ and H+ ion-beam treatment with the ion energy 200 eV and current density 0.15 mA/cm2 at a temperature of 30 oC during 30 min leads to the p-to-n −type overcompensation of the near-surface layer of silicon wafers. The measurements of photovoltage spectra have shown that (i) Ar+ and H+ treatments in like manner lead to the appearance of a photovoltage signal over a wide spectral region due to the formation of p-n-junction on the treated surface, and (ii) photosensitivity of the Ar+ ion-beam treated wafers in the ultraviolet (UV) spectral region (200-400 nm) is much greater as compared to the wafers subjected to H+ ion beam treatment in the same conditions. The main difference in the Ar+ and H+ ion-beam treatment effects is the formation of a thin (5-20 nm) oxygen-containing dielectric layer on the surface of hydrogenated samples and the absence of such layer in case of Ar+ ion-beam treatment.

Temperature Dependence of Etch Rate and Residual Damage in Reactively Ion Etched GaAs and AlGaAs

1988 ◽  
Vol 129 ◽  
Author(s):  
S. J. Pearton ◽  
K. S. Jones ◽  
U. K. Chakabarti ◽  
B. Emerson ◽  
E. Lane ◽  
...  
Keyword(s):  
Thermal Degradation ◽  
Surface Morphology ◽  
Temperature Dependence ◽  
Etch Rate ◽  
Schottky Diodes ◽  
Surface Region ◽  
Ion Etching ◽  
Near Surface ◽  
Temperature Range ◽  
Residual Damage

ABSTRACTThe etch rate of GaAs and AIGaAs during CC12F2:O2 reactive ion etching was measured over the temperature range 50–400ºC. For GaAs, the etch rate increases super-linearly from ∼400Å.min−1 to ∼3000Åmin−1 over this temperature range for a 0.56 W.cm−2, 4 mTorr discharge with a 19:1 CC12F2:O2 mixture. The surface morphology of GaAs undergoes a smooth-to-rough transition near 150ºC, and theresidual damage in the near-surface region appears to decrease with increasing etch temperature. The I-V characteristics of Schottky diodes fabricated on the etched surfaces show ideality factors of 1.001 for 150ºC RIE, although these worsen because of thermal degradation of higher etching temperatures. From AES and XPS data the etched GaAs shows little contamination after etching. In contrast, little temperature dependence of the etch rate of AIGaAs is observed using CC12F2:O2, although once again there is surface degradation for etching temperatures above 150ºC.

Controlled Modifications in the Electrical Properties of Metal/GaAs Junctions

1990 ◽  
Vol 181 ◽  
Author(s):  
M. Eizenberg
Keyword(s):  
Thin Film ◽  
Solid State ◽  
Electrical Properties ◽  
Gaas Substrate ◽  
Surface Region ◽  
Solid State Reactions ◽  
Physical Processes ◽  
Compound Formation ◽  
Near Surface ◽  
Contact Metal

ABSTRACTControlled modifications in the electrical properties of metal/GaAs junctions were obtaind by a few different approaches. The first approach is based on modifications induced by solid state reactions occurring between the metal and GaAs substrate, resulting in compound formation and component redistribution. The characteristics of such contacts can further be modified when the contact metal is alloyed with another metal or with a dopant. The second approach is based on modifying the doping level of the near surface region of the GaAs. Here an enhancement of the barrier height was obtained by heavily counter doping the top GaAs region by recoil implantation of Mg from a Mg thin film irradiated by As− ions. The correlations between the electrical properties of the junctions and the physical processes taking place using the above mentioned approaches are discussed.

Junction Properties of Metal/SrTiO3 Systems

2000 ◽  
Vol 623 ◽  
Author(s):  
Takashi Shimizu ◽  
Hideyo Okushi
Keyword(s):  
Electrical Properties ◽  
Surface Treatment ◽  
Photoelectron Spectroscopy ◽  
Reverse Bias ◽  
Surface States ◽  
Surface Region ◽  
Deep Levels ◽  
Near Surface ◽  
Fermi Level Pinning ◽  
Order Of Magnitude

AbstractElectrical properties of Nb-doped SrTiO3 (STO:Nb) Schottky barrier (SB) junctions have been investigated in detail for a comprehensive understanding of metal/oxide interfaces. Using a high-purity ozone surface treatment, rectification ratio over 9th order of magnitude has been successfully obtained, while without the surface treatment, anomalous large reverse bias leak currents were observed in the current-voltage characteristic of the junctions. The X-ray photoelectron spectroscopy (XPS) shows that carbon contamination which adsorbed the STO:Nb surface in air, induces surface states in the band gap of the STO:Nb, which probably originate the large reverse bias leak currents of the metal/STO:Nb junctions. Thus we present importance, of surface treatment for oxides to obtain controllability and reproducibility of the electrical properties of the oxide devices. Photocapacitance spectroscopy has been performed to investigate deep levels due to bulk defects and impurities in the Au/STO:Nb junctions. The photocapacitance spectra clearly indicate existence of the deep levels in the Au/STO:Nb and the concentration of the deep levels were of the order of 1013∼1015 cm−3. These values are too low to affect the Fermi level pinning at the interface if the deep levels exist in the near surface region of the bulk STO:Nb. We have shown some interesting electrical properties, characteristic of the SB junction of the dielectric oxide compared with that of the conventional semiconductor's. The schematic band diagram of the Au/STO:Nb junction with the intrinsic low permittivity layer at the interface has been proposed, which explains all the characteristic electrical properties. Considering the chemical trend of the SB height (SBH) estimated from the J-V results, we have pointed out the importance of the metal reactivity for understanding the formation mechanism of the SBH.

Surface Conversion Effects in Plasma-Damaged p-GaN

1999 ◽  
Vol 595 ◽  
Author(s):  
X.A. Cao ◽  
S.J. Pearton ◽  
G.T. Dang ◽  
A.P. Zhang ◽  
F. Ren ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Thermal Annealing ◽  
Surface Region ◽  
High Density ◽  
Wet Etching ◽  
Ion Fluxes ◽  
Type Conversion ◽  
Near Surface ◽  
Ion Energies ◽  
Surface Conversion

AbstractThe near-surface (400-500Å) of p-GaN exposed to high density plasmas is found to become more compensated through the introduction of shallow donors. At high ion fluxes or ion energies there can be type-conversion of this surface region. Two different methods for removal of the damaged surface were investigated; wet etching in KOH, which produced self-limiting etch depths or thermal annealing under N2 which largely restored the initial electrical properties.

In Situ Mass Spectroscopy of Recoiled Ion Studies of Degradation Processes in SrBi2Ta2O9 Thin Films During Hydrogen Gas Annealing

1998 ◽  
Vol 541 ◽  
Author(s):  
J. Im ◽  
O. Auciello ◽  
A.R. Krauss ◽  
D.M. Gruen ◽  
R.P.H. Chang ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Mass Spectroscopy ◽  
Surface Composition ◽  
Surface Region ◽  
Strong Relationship ◽  
Xrd Analysis ◽  
Hydrogen Gas ◽  
Hydrogen Annealing ◽  
Near Surface ◽  
Ferroelectric Layer

AbstractIt is known that the forming gas (N2-H2 mixture) annealing process required for microcircuit fabrication results in an unacceptable electrical degradation of SrBi2Ta2O9 (SBT) ferroelectric capacitors due mainly to the interaction of H2 with the ferroelectric layer of the capacitor. We have found a strong relationship between changes in the surface composition of the ferroelectric layer and the electrical properties of SBT capacitors as a result of hydrogen annealing. Mass spectroscopy of recoiled ions (MSRI) analysis revealed a strong reduction in the Bi signal as a function of exposure to hydrogen at high temperatures (∼500°C). The Bi signal reduction correlates with Bi depletion in the SBT surface region. Subsequent annealing in oxygen at temperatures in the range of 700–800°C resulted in the recovery of the MSRI Bi signal, corresponding to the replenishment of Bi in the previously Bi-depleted surface region. XRD analysis (probing the whole SBT film thickness) showed little difference in the XRD spectra of the SBT films before and after hydrogen and oxygen-recovery annealing. The combined results of the MSRI and XRD analyses can be interpreted as an indication that the degradation of the electrical properties of the SBT capacitors, after hydrogen annealing, is mainly due to the degradation of the near surface region of the SBT layer.

scholarly journals Surface Conversion Effects in Plasma-Damaged p-GaN

2000 ◽  
Vol 5 (S1) ◽  
pp. 558-569 ◽  
Author(s):  
X.A. Cao ◽  
S.J. Pearton ◽  
G.T. Dang ◽  
A.P. Zhang ◽  
F. Ren ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Thermal Annealing ◽  
Surface Region ◽  
High Density ◽  
Wet Etching ◽  
Ion Fluxes ◽  
Type Conversion ◽  
Near Surface ◽  
Ion Energies ◽  
Surface Conversion

The near-surface (400-500Å) of p-GaN exposed to high density plasmas is found to become more compensated through the introduction of shallow donors. At high ion fluxes or ion energies there can be type-conversion of this surface region. Two different methods for removal of the damaged surface were investigated; wet etching in KOH, which produced self-limiting etch depths or thermal annealing under N2 which largely restored the initial electrical properties.

Preparation of cross-sectional samples for near-surface TEM studies

1987 ◽  
Vol 45 ◽  
pp. 380-381
Author(s):  
R.C. Dickenson ◽  
K.R. Lawless
Keyword(s):  
Standard Sample ◽  
Surface Region ◽  
Specimen Preparation ◽  
Thick Sheet ◽  
Drill Bit ◽  
Sample Holder ◽  
Metal Interface ◽  
Cross Sectional ◽  
Near Surface ◽  
Cold Worked

In thermal oxidation studies, the structure of the oxide-metal interface and the near-surface region is of great importance. A technique has been developed for constructing cross-sectional samples of oxidized aluminum alloys, which reveal these regions. The specimen preparation procedure is as follows: An ultra-sonic drill is used to cut a 3mm diameter disc from a 1.0mm thick sheet of the material. The disc is mounted on a brass block with low-melting wax, and a 1.0mm hole is drilled in the disc using a #60 drill bit. The drill is positioned so that the edge of the hole is tangent to the center of the disc (Fig. 1) . The disc is removed from the mount and cleaned with acetone to remove any traces of wax. To remove the cold-worked layer from the surface of the hole, the disc is placed in a standard sample holder for a Tenupol electropolisher so that the hole is in the center of the area to be polished.

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