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.

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.

scholarly journals Group-III Nitride ETCH Selectivity IN BCl /Cl ICP Plasmas

1999 ◽  
Vol 4 (S1) ◽  
pp. 823-833 ◽  
Author(s):  
R. J. Shul ◽  
L. Zhang ◽  
C. G. Willison ◽  
J. Han ◽  
S. J. Pearton ◽  
...  
Keyword(s):  
Plasma Chemistry ◽  
Optical Emission ◽  
Group Iii Nitrides ◽  
Plasma Etch ◽  
Source Power ◽  
Group Iii ◽  
Inductively Coupled ◽  
Etch Rates ◽  
Group Iii Nitride ◽  
Coupled Plasmas

Patterning the group-III nitrides has been challenging due to their strong bond energies and relatively inert chemical nature as compared to other compound semiconductors. Plasma etch processes have been used almost exclusively to pattern these films. The use of high-density plasma etch systems, including inductively coupled plasmas (ICP), has resulted in relatively high etch rates (often greater than 1.0 µm/min) with anisotropic profiles and smooth etch morphologies. However, the etch mechanism is often dominated by high ion bombardment energies which can minimize etch selectivity. The use of an ICP-generated BCl3 /Cl2 plasma has yielded a highly versatile GaN etch process with rates ranging from 100 to 8000 Å/min making this plasma chemistry a prime candidate for optimization of etch selectivity. In this study, we will report ICP etch rates and selectivities for GaN, AlN, and InN as a function of BCl3/Cl2 flow ratios, cathode rf-power, and ICP-source power. GaN:InN and GaN:AlN etch selectivities were typically less than 7:1 and showed the strongest dependence on flow ratio. This trend may be attributed to faster GaN etch rates observed at higher concentrations of atomic Cl which was monitored using optical emission spectroscopy (OES).

scholarly journals Development of Micron Sized Photonic Devices Based on Deep GaN Etching

Photonics ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 68
Author(s):  
Karim Dogheche ◽  
Bandar Alshehri ◽  
Galles Patriache ◽  
Elhadj Dogheche
Keyword(s):  
Inductively Coupled Plasma ◽  
Photonic Devices ◽  
Chamber Pressure ◽  
Heterogeneous Structure ◽  
Research Activity ◽  
Etching Depth ◽  
Deep Etching ◽  
Inductively Coupled ◽  
Sio2 Mask ◽  
Gan Etching

In order to design and development efficient III-nitride based optoelectronic devices, technological processes require a major effort. We propose here a detailed review focussing on the etching procedure as a key step for enabling high date rate performances. In our reported research activity, dry etching of an InGaN/GaN heterogeneous structure was investigated by using an inductively coupled plasma reactive ion etching (ICP-RIE). We considered different combinations of etch mask (Ni, SiO2, resist), focussing on the optimization of the deep etching process. A GaN mesa process with an etching depth up to 6 µm was performed in Cl2/Ar-based plasmas using ICP reactors for LEDs dimen sions ranging from 5 to 150 µm². Our strategy was directed toward the mesa formation for vertical-type diode applications, where etch depths are relatively large. Etch characteristics were studied as a function of ICP parameters (RF power, chamber pressure, fixed total flow rate). Surface morphology, etch rates and sidewall profiles observed into InGaN/GaN structures were compared under different types of etching masks. For deep etching up to few microns into the GaN template, we state that a Ni or SiO2 mask is more suitable to obtain a good selectivity and vertical etch profiles. The optimized etch rate was about 200nm/min under moderate ICP conditions. We applied these conditions for the fabrication of micro/nano LEDs dedicated to LiFi applications.

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.

scholarly journals Selective Etching Of Wide Bandgap Nitrides

1997 ◽  
Vol 483 ◽  
Author(s):  
R. J. Shul ◽  
C. G. Willison ◽  
M. M. Bridges ◽  
J. Han ◽  
J. W. Lee ◽  
...  
Keyword(s):  
Group Iii Nitrides ◽  
High Density ◽  
Chamber Pressure ◽  
Rf Power ◽  
Source Power ◽  
Group Iii ◽  
Inductively Coupled ◽  
Patterning Technique ◽  
Etch Rates ◽  
Coupled Plasmas

AbstractHigh-density plasma etching has been an effective patterning technique for the group-III nitrides due to ion fluxes which are 2 to 4 orders of magnitude higher than more conventional reactive ion etch (RIE) systems. GaN etch rates exceeding 0.68 μm/min have been reported in Cl2/H2/Ar inductively coupled plasmas (ICP) at -280 V dc-bias. Under these conditions, the etch mechanism is dominated by ion bombardment energies which can induce damage and minimize etch selectivity. High selectivity etch processes are often necessary for heterostructure devices which are becoming more prominent as growth techniques improve. In this study, we will report high-density ICP etch rates and selectivities for GaN, AIN, and InN as a function of cathode power, ICP-source power, and chamber pressure. GaN:AIN selectivities > 8:1 were observed in a Cl2/Ar plasma at 10 mTorr pressure, 500 W ICP-source power, and 130 W cathode rf-power, while the GaN:InN selectivity was optimized at ∼ 6.5:1 at 5 mTorr, 500 W ICP-source power, and 130 W cathode rf-power.

scholarly journals Group-III Nitride Etch Selectivity in BCl3/Cl2 ICP Plasmas

1998 ◽  
Vol 537 ◽  
Author(s):  
R. J. Shul ◽  
L. Zhang ◽  
C. G. Willison ◽  
J. Han ◽  
S. J. Pearton ◽  
...  
Keyword(s):  
Plasma Chemistry ◽  
Optical Emission ◽  
Group Iii Nitrides ◽  
Plasma Etch ◽  
Source Power ◽  
Group Iii ◽  
Inductively Coupled ◽  
Etch Rates ◽  
Group Iii Nitride ◽  
Coupled Plasmas

AbstractPatterning the group-III nitrides has been challenging due to their strong bond energies and relatively inert chemical nature as compared to other compound semiconductors. Plasma etch processes have been used almost exclusively to pattern these films. The use of high-density plasma etch systems, including inductively coupled plasmas (ICP), has resulted in relatively high etch rates (often greater than 1.0 μm/min) with anisotropic profiles and smooth etch morphologies. However, the etch mechanism is often dominated by high ion bombardment energies which can minimize etch selectivity. The use of an ICP-generated BCl3/Cl2 plasma has yielded a highly versatile GaN etch process with rates ranging from 100 to 8000 Å/min making this plasma chemistry a prime candidate for optimization of etch selectivity. In this study, we will report ICP etch rates and selectivities for GaN, AIN, and InN as a function of BCl3/C12 flow ratios, cathode rf-power, and ICP-source power. GaN:InN and GaN:AIN etch selectivities were typically less than 7:1 and showed the strongest dependence on flow ratio. This trend may be attributed to faster GaN etch rates observed at higher concentrations of atomic Cl which was monitored using optical emission spectroscopy (OES).

Hydrogenation and Defect Creation in GaAs-Based Devices During High Density Plasma Processing

1998 ◽  
Vol 510 ◽  
Author(s):  
T. Maeda ◽  
J. W. Lee ◽  
C. R. Abernathy ◽  
S. J. Pearton ◽  
F. Ren ◽  
...  
Keyword(s):  
Heterojunction Bipolar Transistors ◽  
Inductively Coupled Plasma ◽  
Electron Cyclotron Resonance ◽  
Field Effect Transistors ◽  
High Electron Mobility Transistors ◽  
High Electron ◽  
Source Power ◽  
Ion Energy ◽  
Inductively Coupled ◽  
Self Bias

AbstractThe effects of Inductively Coupled Plasma (ICP) and Electron Cyclotron Resonance (ECR) H2 plasmas on GaAs metal semiconductor field effect transistors (MESFETs), high electron mobility transistors (HEMTs) and heterojunction bipolar transistors (HBTs) have been measured as a function of ion flux, ion energy and process pressure. The chemical effects of hydrogenation have been compared to direct physical bombardment by Ar plasmas under the same conditions. Si dopant passivation in MESFETs and HEMTs and C base-dopant passivation in HBTs produces much larger changes in sheet resistance, breakdown voltage and device gain or transconductance than Ar ion bombardment and suggests that H2-containing plasma chemistries (CH4/H2 for semiconductor etching, SiH4 for dielectric deposition, CHF3 for dielectric etching) should be avoided, or at least the exposure of the surface minimized. In some cases the device degradation is less for higher source power conditions, due to the suppression of cathode dc self-bias and hence ion energy.

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