scholarly journals Inductively Coupled Plasma Etching of III-Nitrides in Cl2/Xe, Cl2/Ar AND Cl2/He

1998 ◽  
Vol 537 ◽  
Author(s):  
Hyun Cho ◽  
Y.B. Hahn ◽  
D.C. Hays ◽  
K.B. Jung ◽  
S.M. Donovan ◽  
...  

AbstractThe role of additive noble gases He, Ar and Xe to Cl2-based Inductively Coupled Plasmas for etching of GaN, AIN and InN were examined. The etch rates were a strong function of chlorine concentration, rf chuck power and ICP source power. The highest etch rates for InN were obtained with Cl2/Xe, while the highest rates for AIN and GaN were obtained with Cl2/He. Efficient breaking of the III-nitrogen bond is crucial for attaining high etch rates. The InN etching was dominated by physical sputtering, in contrast to GaN and AIN. In the latter cases, the etch rates were limited by initial breaking of the III-nitrogen bond. Maximum selectivities of ∼ 80 for InN to GaN and InN to AIN were obtained.

1999 ◽  
Vol 4 (S1) ◽  
pp. 763-768
Author(s):  
Hyun Cho ◽  
Y.B. Hahn ◽  
D.C. Hays ◽  
K.B. Jung ◽  
S.M. Donovan ◽  
...  

The role of additive noble gases He, Ar and Xe to Cl2-based Inductively Coupled Plasmas for etching of GaN, AlN and InN were examined. The etch rates were a strong function of chlorine concentration, rf chuck power and ICP source power. The highest etch rates for InN were obtained with Cl2/Xe, while the highest rates for AlN and GaN were obtained with Cl2/He. Efficient breaking of the III-nitrogen bond is crucial for attaining high etch rates. The InN etching was dominated by physical sputtering, in contrast to GaN and AlN. In the latter cases, the etch rates were limited by initial breaking of the III-nitrogen bond. Maximum selectivities of ∼ 80 for InN to GaN and InN to AlN were obtained.


1998 ◽  
Vol 512 ◽  
Author(s):  
Hyun Cho ◽  
T. Maeda ◽  
J. D. MacKenzie ◽  
S. M. Donovan ◽  
C. R. Abemathy ◽  
...  

ABSTRACTAnisotropic pattern transfer has been performed for GaN, InN and AIN in Cl2/Ar, BI3/Ar and BBr3/Ar Inductively Coupled Plasmas(ICP). Controlled etch rates in the range of 500–1500Å·min−1 are obtained for III-nitride materials in Cl2/Ar chemistry. Etch selectivities of 100:1 were achieved for InN over both GaN and AIN in the BI3 mixtures, while for BBr3 discharges values of 100:1 for InN over AIN and 25:1 for InN over GaN were measured.


1997 ◽  
Vol 51 (5) ◽  
pp. 607-616 ◽  
Author(s):  
John W. Olesik ◽  
Jeffery A. Kinzer ◽  
Garrett J. McGowan

An instrument to obtain optical emission and laser-induced fluorescence images of atom or ion clouds, each produced from isolated, monodisperse droplets of sample in an inductively coupled plasma, is described. An excimer laser pumped dye laser is used to produce a large (28-mm × 24-mm) beam for saturated fluorescence from atoms or ions throughout a large portion of the ICP. An intensified charge-coupled device (ICCD) detects optical emission or laser induced fluorescence snapshot images at the focal plane of an aberration-corrected slitless spectrograph. Images produced from a single laser pulse can be detected. Double-exposure emission images with 1-μs gate times can be acquired to monitor the movement of atom or ion clouds produced from a single droplet of sample solution. Variations in the number of atoms or ions produced as a function of time (or height) in the plasma can be monitored. Excitation in the plasma can be assessed from ratios of emission to fluorescence intensities.


1981 ◽  
Vol 35 (4) ◽  
pp. 380-384 ◽  
Author(s):  
Robert S. Houk ◽  
Harry J. Svec ◽  
Velmer A. Fassel

Mass spectra have been obtained of species in the axial channel of an inductively coupled argon plasma by extracting ions from the inductively coupled plasma into a vacuum system housing a quadrupole mass spectrometer. Ionization temperatures ( Tion) are obtained from relative count rates of m/z-resolved ions according to two general types of ionization equilibrium considerations: (a) the ratio of doubly/singly charged ions of the same element, and (b) the ratio of singly charged ions from two elements of different ionization energy. The Tion values derived from measurement of Ar+2/Ar+, Ba+2/Ba+, Sr+2/Sr+, and Cd+/I+ are all greater than those expected from excitation temperatures measured by other workers. The latter three values for Tion are in reasonable agreement with values obtained by optical spectrometry for a variety of argon inductively coupled plasmas.


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.


2008 ◽  
Vol 74 (2) ◽  
pp. 155-161 ◽  
Author(s):  
K. T. A. L. BURM

AbstractAn electronic identity relation, relating capacitively coupled plasma sources to corresponding inductively coupled plasma sources, has been derived, starting from the Maxwell relations for matter and the characteristics of a capacitor and of an inductor. Furthermore, the breakdown conditions for both capacitively coupled plasmas and for inductively coupled plasmas as well as their optimal operation frequency ranges are discussed.


2011 ◽  
Vol 25 (31) ◽  
pp. 4237-4240 ◽  
Author(s):  
JONG CHEON PARK ◽  
JIN KON KIM ◽  
TAE GYU KIM ◽  
DEUG WOO LEE ◽  
HYUN CHO ◽  
...  

High density plasma etching of SnO 2 and ZnO films was performed in chlorine- ( Cl 2/ Ar and BCl 3/ Ar ) and fluorine-based ( CF 4/ Ar and SF 6/ Ar ) inductively coupled plasmas. The etch process window for fabricating metal oxide nanowires with high aspect ratios including high and controllable etch rates, high etch selectivities to mask material and high anisotropy was established. Maximum etch rates of ~2050 Å/minute ( BCl 3/ Ar ) and ~1950 Å/minute ( SF 6/ Ar ) for ZnO , and ~1950 Å/minute ( Cl 2/ Ar ) and ~2000 Å/minute ( SF 6/ Ar ) for SnO 2 were obtained. Ni was found to provide very high etch selectivities with maximum values of ~67 to SnO 2 and ~17 to ZnO , respectively.


1997 ◽  
Vol 483 ◽  
Author(s):  
Hyun Cho ◽  
C. B. Vartuli ◽  
C. R. Abernathy ◽  
S. M. Donovan ◽  
S. J. Pearton ◽  
...  

AbstractCl2-based Inductively Coupled Plamas with low additional dc self-biases(−100V) produce convenient etch rates(500–1500Å.min−1) for GaN, AIN, InN, InAiN and InGaN. A systematic study of the effects of additive gas(Ar, N2, H2), discharge composition and ICP source power and chuck power on etch rate and surface morphology has been performed. The general trends are to go through a maximum in etch rate with percent C12 in the discharge for all three mixtures, and to have an increase(decrease) in etch rate with source power(pressure). Since the etching is strongly ion-assisted, anisotropic pattern transfer is readily achieved. Maximum etch selectivities of approximately 6 for InN over the other nitrides were obtained.


2021 ◽  
Vol 59 (2) ◽  
pp. 121-126
Author(s):  
Ji Hun Um ◽  
Byoung Su Choi ◽  
Woo Sik Jang ◽  
Sungu Hwang ◽  
Dae-Woo Jeon ◽  
...  

α-Ga2O3 has the largest bandgap (~5.3 eV) among the five polymorphs of Ga2O3 and is a promising candidate for high power electronic and optoelectronic devices. To fabricate various device structures, it is important to establish an effective dry etch process which can provide practical etch rate, smooth surface morphology and low ion-induced damage. Here, the etch characteristics of α-Ga2O3 epitaxy film were examined in two fluorine-based (CF4/Ar and SF6/Ar) inductively coupled plasmas. Under the same source power, rf chuck power and process pressure, an Ar-rich composition of CF4/Ar and an SF6-rich composition of SF6/Ar produced the highest etch rates. Monotonic increase in the etch rate was observed as the source power and rf chuck power increased in the 2CF4/13Ar discharges, and a maximum etch rate of ~855 Å/min was obtained at a 500 W source power, 250 W rf chuck power, and 2 mTorr pressure. A smooth surface morphology with normalized roughness of less than ~1.38 was achieved in the 2CF4/13Ar and 13SF6/2Ar discharges under most of the conditions examined. The features etched into the α-Ga2O3 layer using a 2CF4/13Ar discharge with 2 mTorr pressure showed good anisotropy with a vertical sidewall profile.


1999 ◽  
Vol 4 (S1) ◽  
pp. 823-833 ◽  
Author(s):  
R. J. Shul ◽  
L. Zhang ◽  
C. G. Willison ◽  
J. Han ◽  
S. J. Pearton ◽  
...  

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).


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