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 ◽  
...  

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.

1999 ◽  
Vol 595 ◽  
Author(s):  
A.P. Zhang ◽  
G. Dang ◽  
F. Ren ◽  
X.A. Cao ◽  
H. Cho ◽  
...  

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.


1998 ◽  
Vol 510 ◽  
Author(s):  
T. Maeda ◽  
J. W. Lee ◽  
C. R. Abernathy ◽  
S. J. Pearton ◽  
F. Ren ◽  
...  

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.


1998 ◽  
Vol 512 ◽  
Author(s):  
J. J. Wang ◽  
Hyun Cho ◽  
E. S. Lambers ◽  
S. J. Peartont ◽  
M. Ostling ◽  
...  

ABSTRACTA parametric study of the etching characteristics of 6H p+ and n+ SiC and thin film SiC0.8N0.2 in Inductively Coupled Plasma NF3/O2 and NF3/Ar discharges has been performed. The etch rates in both chemistries increase monotonically with NF3 percentage and rf chuck power reaching 3500Å·min−1 for SiC and 7500 Å·min−1 for SiCN. The etch rates go through a maximum with increasing ICP source power, which is explained by a trade-off between the increasing ion flux and the decreasing ion energy. The anisotropy of the etched features is also a function of ion flux, ion energy and atomic fluorine neutral concentration. Indium-tinoxide( ITO) masks display relatively good etch selectivity over SiC(maximum of 70:1) while photoresist etches more rapidly than SiC. The surface roughness of SiC is essentially independent of plasma composition for NF3/O2 discharges, while extensive surface degradation occurs for SiCN under high NF3:O2 conditions. The high ion flux available in the ICP tool allows etching even at very low dc self-biases, ≤ −10V, leading to very low damage pattern transfer.


2000 ◽  
Vol 147 (2) ◽  
pp. 719 ◽  
Author(s):  
A. P. Zhang ◽  
G. Dang ◽  
F. Ren ◽  
X. A. Cao ◽  
H. Cho ◽  
...  

2006 ◽  
Vol 21 (10) ◽  
pp. 2440-2443 ◽  
Author(s):  
Shinn-Shyong Tzeng ◽  
Pei-Lun Wang ◽  
Ting-Yu Wu ◽  
Kao-Shao Chen ◽  
San-Der Chyou ◽  
...  

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.


1998 ◽  
Vol 512 ◽  
Author(s):  
R. J. Shul ◽  
C. I. H. Ashby ◽  
C. G. Willison ◽  
L. Zhang ◽  
J. Han ◽  
...  

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.


2000 ◽  
Vol 639 ◽  
Author(s):  
Rajwinder Singh ◽  
C. R. Eddy ◽  
T.D. Moustakas ◽  
H.M. Ng

ABSTRACTThe effects of inductively-coupled plasma etching on the quality of ohmic contacts to etched n- GaN are reported. A high density chlorine plasma and a range of rf bias power levels (incident ion energies) are employed to etch n-GaN films with varying doping levels. Resulting plasma damage degrades contact ohmicity in all cases examined. At moderate levels of rf bias power the extent of this degradation for nitride layers with lower doping levels (mid-1017 cm−3) is similar to the degradation for nitride layers with higher doping levels. With increased rf bias, the degradation becomes more severe in films with higher carrier concentration. Annealing at 700 °C rapidly improves the contact quality. Studies of cumulative annealing time, up to 160 seconds, show that the improvement in contact quality takes place within the first twenty seconds of annealing.


Author(s):  
X. A. Cao ◽  
A. P. Zhang ◽  
G. T. Dang ◽  
H. Cho ◽  
F. Ren ◽  
...  

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