scholarly journals High-Density Plasma-Induced Etch Damage of GaN

1999 ◽  
Vol 573 ◽  
Author(s):  
R. J. Shul ◽  
L. Zhang ◽  
A. G. Baca ◽  
C. G. Willison ◽  
J. Han ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Critical Dimension ◽  
Group Iii Nitrides ◽  
High Plasma ◽  
High Density ◽  
Plasma Flux ◽  
Plasma Etch ◽  
Critical Dimensions ◽  
Profile Control ◽  
Density Plasma

ABSTRACTAnisotropic, smooth etching of the group-Ill nitrides has been reported at relatively high rates in high-density plasma etch systems. However, such etch results are often obtained under high dc-bias and/or high plasma flux conditions where plasma induced damage can be significant. Despite the fact that the group-III nitrides have higher bonding energies than more conventional III–V compounds, plasma-induced etch damage is still a concern. Attempts to minimize such damage by reducing the ion energy or increasing the chemical activity in the plasma often result in a loss of etch rate or anisotropy which significantly limits critical dimensions and reduces the utility of the process for device applications requiring vertical etch profiles. It is therefore necessary to develop plasma etch processes which couple anisotropy for critical dimension and sidewall profile control and high etch rates with low-damage for optimum device performance. In this study we report changes in sheet resistance and contact resistance for n- and p-type GaN samples exposed to an Ar inductively coupled plasma (ICP). In general, plasma-induced damage was more sensitive to ion bombardment energies as compared to plasma flux. In addition, p-GaN was typically more sensitive to plasma-induced damage as compared to n-GaN.

Inductively Coupled High-Density Plasma-Induced Etch Damage of GaN MESFETs

2000 ◽  
Vol 622 ◽  
Author(s):  
R. J. Shul ◽  
L. Zhang ◽  
A. G. Baca ◽  
C. G. Willison ◽  
J. Han ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Ion Bombardment ◽  
Critical Dimension ◽  
High Plasma ◽  
Substrate Material ◽  
Device Performance ◽  
Inductively Coupled ◽  
Profile Control ◽  
Etch Rates ◽  
Anisotropic Etch

ABSTRACTThe fabrication of a wide variety of GaN-based photonic and electronic devices depends on dry etching, which typically requires ion-assisted removal of the substrate material. Under conditions of both high plasma flux and energetic ion bombardment, GaN etch rates greater than 0.5 νm/min and anisotropic etch profiles are readily achieved in Inductively Coupled Plasma (ICP) etch systems. Unfortunately, under these conditions plasma-induced damage often occurs. Attempts to minimize such damage by reducing the ion energy or increasing the chemical activity in the plasma often result in a loss of etch rate or profile control which can limit dimensional control and reduce the utility of the process for device applications requiring anisotropic etch profiles. It is therefore necessary to develop plasma etch processes which couple anisotropy for critical dimension and sidewall profile control and high etch rates with low-damage for optimum device performance. In this study we report changes in source resistance, reverse breakdown voltage, transconductance, and drain saturation current for GaN MESFET structures exposed to an Ar ICP plasma. In general, device performance was sensitive to ion bombardment energy and ion flux.

GaN Etching in BCl3/Cl2 Plasmas

1998 ◽  
Vol 512 ◽  
Author(s):  
R. J. Shul ◽  
C. I. H. Ashby ◽  
C. G. Willison ◽  
L. Zhang ◽  
J. Han ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Plasma Chemistry ◽  
High Plasma ◽  
High Density ◽  
Chamber Pressure ◽  
Plasma Etch ◽  
Source Power ◽  
Inductively Coupled ◽  
High Volatility ◽  
Gan Etching

ABSTRACTGaN etching can be affected by a wide variety of parameters including plasma chemistry and plasma density. Chlorine-based plasmas have been the most widely used plasma chemistries to etch GaN due to the high volatility of the GaClx and NClx etch products. The source of Cl and the addition of secondary gases can dramatically influence the etch characteristics primarily due to their effect on the concentration of reactive Cl generated in the plasma. In addition, high-density plasma etch systems have yielded high quality etching of GaN due to plasma densities which are 2 to 4 orders of magnitude higher than reactive ion etch (RIE) plasma systems. The high plasma densities enhance the bond breaking efficiency of the GaN, the formation of volatile etch products, and the sputter desorption of the etch products from the surface. In this study, we report GaN etch results for a high-density inductively coupled plasma (ICP) as a function of BCl3:Cl2 flow ratio, dc-bias, chamber pressure, and ICP source power. GaN etch rates ranging from ∼100 Å/min to > 8000 Å/min were obtained with smooth etch morphology and anisotropic profiles.

Characterization of the CH4/H2/Ar High Density Plasma Etch Process for HgCdTe

1996 ◽  
Vol 450 ◽  
Author(s):  
C. R. Eddy ◽  
D. Leonhardt ◽  
V. A. Shamamian ◽  
R. T. Holm ◽  
O. J. Glembocki ◽  
...  
Keyword(s):  
Surface Temperature ◽  
Plasma Etching ◽  
High Density ◽  
Scanning Electron Micrographs ◽  
Plasma Etch ◽  
Ion Energy ◽  
Residual Damage ◽  
Hall Effect Measurements ◽  
Density Plasma

ABSTRACTHigh density plasma etching of Hg1−xCdxTe in CH4/H2/Ar chemistry is examined using mass spectroscopy with careful surface temperature monitoring. The dominant etch products are monitored as a function of surface temperature (15–200°C), ion energy (20–200 eV), total pressure (0.5–5 mTorr), microwave power (200–400 W), and flow fraction of methane in the etch gas mixture (0–30%). In addition, observations are made regarding the regions of parameter space which are best suited to anisotropie, low damage etch processing. These observations are compared with previous results in the form of scanning electron micrographs of etched features for anisotropy evaluation and Hall effect measurements for residual damage. Insights to the overall etch mechanism are given.

High Density Plasma Damage Induced in n-GaN Schottky Diodes Using Cl2/Ar Discharges

1999 ◽  
Vol 595 ◽  
Author(s):  
A.P. Zhang ◽  
G. Dang ◽  
F. Ren ◽  
X.A. Cao ◽  
H. Cho ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Schottky Barrier Height ◽  
Schottky Diodes ◽  
High Density ◽  
Plasma Damage ◽  
Source Power ◽  
Ion Energy ◽  
Inductively Coupled ◽  
Self Bias ◽  
Density Plasma

AbstractThe effects of dc chuck self-bias and high density source power (which predominantly control ion energy and ion flux, respectively) on the electrical properties of n-GaN Schottky diodes exposed to Inductively Coupled Plasma of Cl2/Ar were examined. Both parameters were found to influence the diode performance, by reducing the reverse breakdown voltage and Schottky barrier height. All plasma conditions were found to produce a nitrogen-deficient surface, with a typical depth of the non-stoichiometry being ∼500 Å. Post-etch annealing was found to partially restore the diode characteristics.

scholarly journals High Density Plasma Damage Induced in n-GaN Schottky Diodes Using Cl2/Ar Discharges

2000 ◽  
Vol 5 (S1) ◽  
pp. 831-837
Author(s):  
A.P. Zhang ◽  
G. Dang ◽  
F. Ren ◽  
X.A. Cao ◽  
H. Cho ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Schottky Barrier Height ◽  
Schottky Diodes ◽  
High Density ◽  
Plasma Damage ◽  
Source Power ◽  
Ion Energy ◽  
Inductively Coupled ◽  
Self Bias ◽  
Density Plasma

The effects of dc chuck self-bias and high density source power (which predominantly control ion energy and ion flux, respectively) on the electrical properties of n-GaN Schottky diodes exposed to Inductively Coupled Plasma of Cl2/Ar were examined. Both parameters were found to influence the diode performance, by reducing the reverse breakdown voltage and Schottky barrier height. All plasma conditions were found to produce a nitrogen-deficient surface, with a typical depth of the non-stoichiometry being ∼ 500 Å. Post-etch annealing was found to partially restore the diode characteristics.

Use of Novel Hydrofluorocarbon and Iodofluorocarbon Chemistries for a High Aspect Ratio Via Etch in a High Density Plasma Etch Tool

1998 ◽  
Vol 145 (12) ◽  
pp. 4305-4312 ◽  
Author(s):  
Simon Karecki ◽  
Laura Pruette ◽  
Rafael Reif ◽  
Terry Sparks ◽  
Laurie Beu ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
High Density ◽  
Plasma Etch ◽  
Density Plasma

Formation of loops on the surface of carbon nanofibers synthesized by plasma-enhanced chemical vapor deposition using an inductively coupled plasma reactor

2006 ◽  
Vol 21 (10) ◽  
pp. 2440-2443 ◽  
Author(s):  
Shinn-Shyong Tzeng ◽  
Pei-Lun Wang ◽  
Ting-Yu Wu ◽  
Kao-Shao Chen ◽  
San-Der Chyou ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Carbon Nanofibers ◽  
Vapor Deposition ◽  
Inductively Coupled Plasma ◽  
Plasma Reactor ◽  
Chemical Vapor ◽  
High Density ◽  
Inductively Coupled ◽  
Thermal Cvd ◽  
Density Plasma

Carbon nanofibers (CNFs) were synthesized by both high-density plasma-enhanced chemical vapor deposition (CVD) and thermal CVD. The growth in the former was carried out in an inductively coupled plasma (ICP) reactor. The multilayer loop structure, which was reported to be found on both the inner and outer surfaces of cup-stacked-type CNFs grown using thermal CVD only after heat treatment above 1500 °C, was observed in the as-grown CNFs only on the outer surface using ICP-CVD. The dangling bonds caused by plasma etching and the bonding between edge carbon atoms aided by the high-density plasma are considered the main reasons of the formation of multilayer loops.

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