Inductively coupled plasma etching of GaN using BCl<sub>3</sub>/Cl<sub>2</sub>chemistry and photoluminescence studies of the etched samples

Remashan, K.; Chua, Soo-Jin; Ramam, A.; Prakash, Savarimuthu; Liu, W

doi:10.1088/0268-1242/15/4/313

Cited by 15 publications

(5 citation statements)

References 23 publications

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“…The dc bias decreases by ∼15 V as the Cl 2 concentration increases from 0-100% and so is not the cause of the increased etch rate. Similar behaviour has been reported in GaN etching[18,19] where etch rate was generally found to increase with Cl 2 concentration. These studies also reported increases in ion current density and amounts of Cl radicals with increased Cl 2 concentration.…”

supporting

confidence: 82%

Selective etching of AlGaInP laser structures in a BCl₃/Cl₂inductively coupled plasma

Edwards

Westwood

Smowton

2006

Semicond. Sci. Technol.

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The etch rate of AlGaInP-based laser structures and selectivity, with respect to SiO 2 , are reported as a function of inductively coupled plasma (ICP) process parameters for a BCl 3 /Cl 2 etch chemistry. At room temperature InCl 3 , a reaction product of In in this environment, is involatile, whereas the products of etching SiO 2 are relatively volatile resulting in low selectivity (∼4:1). Temperature is the most important variable for improving etch rate and selectivity. At 190 • C it is possible to obtain an etch rate up to 0.7 µm min −1 and a selectivity as high as 17:1. It is shown that increasing the ICP power increases the etch rate of AlGaInP but decreases the selectivity, whereas increased reactive ion etching (RIE) power results in improved etch rate and selectivity. The etch rate is also found to be higher at lower chamber pressures although again with little or no change in selectivity. These results are consistent with an AlGaInP etch rate that is dependent on both dc bias and ion flux, in contrast to a SiO 2 etch mechanism that is relatively independent of dc bias but strongly dependent on ion flux. With total gas flow kept constant the etch rate and selectivity are found to increase with the fraction of Cl 2 present. The addition of Ar to the gas mix does increase the etch rate, reaching a maximum at around 70% Ar, but without any significant effect on selectivity.

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supporting

confidence: 82%

Selective etching of AlGaInP laser structures in a BCl₃/Cl₂inductively coupled plasma

Edwards

Westwood

Smowton

2006

Semicond. Sci. Technol.

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“…The diameter and the pitch of the patterned circular Ni dots were 120 nm and 1 μm, respectively. The Ni layer acted as a mask for GaN RIE, using a BCl 3 /Cl 2 gas mixture [27]. RIE was carried out by applying 50 W power at pressure of 10 −2 Torr, with gas flow rates of 7 sccm BCl 3 and 1 sccm Cl 2 and resulted to GaN etch rate of 15 nm min −1 .…”

Section: Top-down Gan Nw Formation Processmentioning

confidence: 99%

Nanofabrication of normally-off GaN vertical nanowire MESFETs

et al. 2019

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Gallium nitride (GaN) all-around (wrap) gate vertical nanowire (V-NW) field-effect transistors (FETs) are favorable for enhanced electrostatic control of the gate and selectivity for normally on/off operation. In this work, GaN V-NW FETs with a Schottky barrier gate (V-NW MESFETs), were fabricated for the first time. A nanofabrication process with comprehensive description of all processing steps is reported. It was validated with the demonstration of GaN V-NW MESFETs consisting of an array of 900 (30 × 30) GaN NWs with the narrowest until now reported diameter of 100 nm and all-around gate length of 250 nm. The GaN NWs were formed by a top-down approach, which combines conventional nanopatterning techniques and anisotropic wet etching of an initial GaN epilayer, grown by plasma assisted molecular beam epitaxy on a sapphire (0001) substrate. DC I–V characteristics exhibited normally-off operation and threshold voltage of +0.4 V, due to electron depletion region from the all-around Schottky barrier. A maximum drain-source current density (Jds) of 330 A cm−2 and maximum transconductance (gm) of 285 S cm−2 were obtained from I–V measurements. The results and directions for further optimization were discussed.

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“…Inductively coupled plasma reactive ion etching (ICP-RIE) is the preferred technique for the processing of these materials, as it allows high etch rates due to the high density plasma and provides smoother surface morphology than conventional RIE etching because of low surface damage [1]. ICP etching of polar (0001) c-plane GaN has been thoroughly investigated and is well understood [2][3][4][5][6][7]. However, very few reports exist on the etching of semi-polar (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22) GaN, non-polar (11)(12)(13)(14)(15)(16)(17)(18)(19)(20) aplane GaN and high aluminum content Al x Ga 1−x N alloys of polar, semi-polar and non-polar orientations [8][9][10][11]14].…”

Section: Introductionmentioning

confidence: 99%

ICP-RIE etching of polar, semi-polar and non-polar AlN: comparison of Cl₂/Ar and Cl₂/BCl₃/Ar plasma chemistry and surface pretreatment

Shah

Rahman

Bhattacharya

2014

Semicond. Sci. Technol.

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We report a comprehensive investigation of inductively-coupled plasma reactive ion etching (ICP-RIE) of polar (0001) c-plane, semi-polar (11-22) and non-polar (11-20) a-plane AlN epilayers and show that under optimized conditions a combination of BCl 3 -based surface oxide removal pretreatment and Cl 2 /Ar ICP etching allows fast etch rates (750 nm min −1 ) with a smooth surface morphology. We compare samples of different orientation etched in Cl 2 /Ar and Cl 2 /BCl 3 /Ar plasmas, with and without BCl 3 /Ar ICP pretreatment, and show that the effective removal of surface oxide is a crucial step for reliable ICP-RIE etching of AlN layers. For such pretreated samples, optimization of etch parameters such as RF power, ICP power, and chamber pressure then permit very high etch rates to be obtained with a smooth surface morphology. We also study the effect of varying the BCl 3 fraction in BCl 3 /Cl 2 /Ar plasmas on the etch rate and surface morphology and find that increasing the BCl 3 fraction reduces the etch rate for AlN. However, above 20% BCl 3 content, samples with and without pre-treatment show similar etch rates.

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Inductively coupled plasma etching of GaN using BCl₃/Cl₂chemistry and photoluminescence studies of the etched samples

Cited by 15 publications

References 23 publications

Selective etching of AlGaInP laser structures in a BCl₃/Cl₂inductively coupled plasma

Selective etching of AlGaInP laser structures in a BCl₃/Cl₂inductively coupled plasma

Nanofabrication of normally-off GaN vertical nanowire MESFETs

ICP-RIE etching of polar, semi-polar and non-polar AlN: comparison of Cl₂/Ar and Cl₂/BCl₃/Ar plasma chemistry and surface pretreatment

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Inductively coupled plasma etching of GaN using BCl3/Cl2chemistry and photoluminescence studies of the etched samples

Cited by 15 publications

References 23 publications

Selective etching of AlGaInP laser structures in a BCl3/Cl2inductively coupled plasma

Selective etching of AlGaInP laser structures in a BCl3/Cl2inductively coupled plasma

Nanofabrication of normally-off GaN vertical nanowire MESFETs

ICP-RIE etching of polar, semi-polar and non-polar AlN: comparison of Cl2/Ar and Cl2/BCl3/Ar plasma chemistry and surface pretreatment

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Product

Resources

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Inductively coupled plasma etching of GaN using BCl₃/Cl₂chemistry and photoluminescence studies of the etched samples

Selective etching of AlGaInP laser structures in a BCl₃/Cl₂inductively coupled plasma

Selective etching of AlGaInP laser structures in a BCl₃/Cl₂inductively coupled plasma

ICP-RIE etching of polar, semi-polar and non-polar AlN: comparison of Cl₂/Ar and Cl₂/BCl₃/Ar plasma chemistry and surface pretreatment