Characteristics of GaN thin films by inductively coupled plasma etching with Cl2/BCl3 and Cl2/Ar

Abstract

GaN thin films were etched by inductively coupled plasma (ICP). The effects of BCl 3 and Ar with different Cl 2 fraction are studied and compared. The ICP power and RF power are also altered to investigate the different effects by using Cl 2 /BCl 3 or Cl 2 /Ar as etching gases. The etch rate and surface morphology of the etched surface are characterized by using surface profiler, scanning electron microscopy and atomic force microscopy. The root-mean-square roughness values are systematically compared. It is found that the etch rates of Cl 2 /Ar are higher than that of the Cl 2 /BCl 3 in the Cl 2 fraction ranging from 10 to 90%. When the ICP power is increased, the RMS roughness of GaN surface after ICP etching shows reverse trend between Cl 2 /BCl 3 and Cl 2 /Ar gas mixture. The results indicate quite different features using Cl 2 /BCl 3 and Cl 2 /Ar for GaN ICP etcing under the same conditions.

Optimization of Mesa Etch for a Quasi-Vertical GaN Schottky Barrier Diode (SBD) by Inductively Coupled Plasma (ICP) and Device Characteristics

“…Therefore, the formation of highly anisotropic profiles of the mesa structure in the etching process is crucial for quasi-vertical GaN devices [6]. Most efforts on the reduction of surface damage and roughness of mesas [7] have been made using inductively coupled plasma (ICP) power, radio frequency 2 of 13 (RF) power, the ratio of etching gas, flow rate [8][9][10][11], and mask selection [12]. Moreover, the steepness of the mesa sidewall has also been investigated using ICP dry etching [13].…”

Development of Micron Sized Photonic Devices Based on Deep GaN Etching

“…Dislocations were created during growth due to the lattice mismatch between the sapphire substrate and GaN [20][21][22]. Usually, the Cl 2 /Ar based plasma shows correct results such as high etch rates, anisotropic profile and a smooth surface of homogeneous GaN [23,24]. 2021, 8, x FOR PEER REVIEW 2 of 7 and microelectromechanical system devices for device isolation, waveguide or vertical channel formation [13][14][15].…”

“…Dislocations were created during growth due to the lattice mismatch between the sapphire substrate and GaN [20][21][22]. Usually, the Cl2/Ar based plasma shows correct results such as high etch rates, anisotropic profile and a smooth surface of homogeneous GaN [23,24]. For the formation of the etching mask, we considered three possible combinations: photoresist (4 µm thick AZ9260), SiO 2 and Ni layers with a thickness of 600 nm and 520 nm, respectively.…”

A Selective Etching Route for Large-Scale Fabrication of β-Ga2O3 Micro-/Nanotube Arrays

“…The vacuum chamber is exhausted by a molecular pump. The optimized ICP etching conditions for GaN were performed from our previous work [22,29,30], the 90%Cl 2 /10%BCl 3 (48/6 sccm) was used with the RF/ICP power fixed at 100/300 W, while the DC bias voltage generated was 460 V, the chamber pressure and helium backing were kept at 10 mTorr and 6 Torr, and the sample was etched for 5 min.…”