A Review: Inductively Coupled Plasma Reactive Ion Etching of Silicon Carbide (original) (raw)
Related papers
Deep reactive ion etching of silicon carbide
Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, 2001
In this article, we describe more than 100-m-deep reactive ion etching ͑RIE͒ of silicon carbide ͑SiC͒ in oxygen-added sulfur hexafluoride ͑SF 6 ) plasma. We used a homemade magnetically enhanced, inductively coupled plasma reactive ion etcher ͑ME-ICP-RIE͒ and electroplated nickel masks. First, 5 h etching experiments using etching gases with 0%, 5%, 10% and 20% oxygen were performed by supplying rf power of 150 and 130 W to an ICP antenna and a sample stage, respectively. They demonstrated a maximum etch rate of 0.45 m/min and residue-free etching in the case of 5% oxygen addition. Observation of the cross sections of etched samples using a scanning electron microscope confirmed a microloading effect, which is reduction of the etched depth with a decrease in the mask opening width. Next, a 7 h etching experiment using an etching gas with 5% oxygen was performed by increasing the rf power to the sample stage to 150 W. This yielded an etched depth of 216 m.
Scientific reports, 2017
This study presents a detailed fabrication method, together with validation, discussion, and analysis, for state-of-the-art silicon carbide (SiC) etching of vertical and bevelled structures by using inductively coupled plasma reactive ion etching (ICP-RIE) for microelectronic applications. Applying different gas mixtures, a maximum bevel angle of 87° (almost vertical), large-angle bevels ranging from 40° to 80°, and small-angel bevels ranging from 7° to 17° were achieved separately using distinct gas mixtures at different ratios. We found that SF6 with additive O2 was effective for vertical etching, with a best etching rate of 3050 Å/min. As for the large-angle bevel structures, BCl3 + N2 gas mixtures show better characteristics, exhibiting a controllable and large etching angle range from 40° to 80° through the adjustment of the mixture ratio. Additionally, a Cl2 + O2 mixture at different ratios is applied to achieve a small-angel bevels ranging from 7° to 17°. A minimum bevel ange...
High-temperature etching of SiC in SF6/O2 inductively coupled plasma
Scientific Reports
In this work, we demonstrate an effective way of deep (30 µm depth), highly oriented (90° sidewall angle) structures formation with sub-nanometer surface roughness (Rms = 0.7 nm) in silicon carbide (SiC). These structures were obtained by dry etching in SF6/O2 inductively coupled plasma (ICP) at increased substrate holder temperatures. It was shown that change in the temperature of the substrate holder in the range from 100 to 300 °C leads to a sharp decrease in the root mean square roughness from 153 to 0.7 nm. Along with this, it has been established that the etching rate of SiC also depends on the temperature of the substrate holder and reaches its maximum (1.28 µm/min) at temperatures close to 150 °C. Further temperature increase to 300 °C does not lead to the etching rate rising. The comparison of the results of the thermally stimulated process and the etching with a water-cooled substrate holder (15 °C) is carried out. Plasma optical emission spectroscopy was carried out at di...
IOP Conference Series: Materials Science and Engineering, 2018
The features of the formation of non-vertical profiles on 4H-SiC by reactive-ion etching (RIE) using various masking coatings are studied. The formation of 4H-SiC mesa structures was carried out using automated airlock reactive-ion etching and plasma etching system "Caroline PE 15" with the ICP-source of plasma in a gas mixture of SF6, O 2 and Ar. Using photoresist AZ4533 as a mask, mesa structures with a wall inclination angle of more than 130° were obtained at the etching rate of 4H-SiC was ~0.5 μm/min. The developed technology of dry etching can be further used in the preparation of avalanche photodiodes or power electronics devices.
Electrochemical etching of silicon carbide
Journal of Solid State Electrochemistry, 1999
Both n-and p-type SiC of dierent doping levels were electrochemically etched by HF. The etch rate (up to 1.5 lm/min) and the surface morphology of p-type 6H-SiC were sensitive to the applied voltage and the HF concentration. The electrochemical valence of 6.3 0.5 elementary charge per SiC molecule was determined. At p-n junctions (p-type layer on a n-type 6H-SiC substrate) a selective etching of the p-type epilayer could be achieved. For a planar 6H-4H polytype junction (n-type, both polytypes with equal doping concentrations) the 4H region was selectively etched under UV illumination. Thus polytype junctions could be marked by electrochemical etching. With HCl instead of HF no etching of SiC occurs, but a SiO 2 layer (thickness up to 8 lm) is formed by anodic oxidation.
Journal of Applied Physics, 2003
4H silicon carbide ͑SiC͒ substrates were dry etched in an inductively coupled plasma ͑ICP͒ system, using SF 6 /O 2 gas mixtures. Etch rate and etch mechanisms have been investigated as a function of oxygen concentration in the gas mixture, ICP chuck power, work pressure, and flow rate. Corresponding to these etch conditions, surface information of the etched SiC has been obtained by x-ray photoelectron spectroscopy measurements. The fact that no obvious Si-Si and Si-F bonds were detected on the etched surface of SiC in all our etch experiments suggests efficient removal of Si atoms as volatile products during the processes. However, various kinds of C-F bonds have been detected on the etched SiC surface and the relative intensities of these bonds vary with the etch conditions. In addition, the nature of the incorporated F atoms on the etched surface also depends strongly on etch conditions, which was identified by the change of the relative ratio between semi-ionic and covalent carbon fluorine bonds. The electrical behavior for different bond structures on the etched SiC surface can be one of the basic reasons affecting related devices.
Surface characterization of inductively coupled plasma etched SiC in SF6/O2
Microelectronic Engineering, 2003
An inductively coupled plasma (ICP) system has been used to dry etch 4H silicon carbide (SiC) substrate samples in SF / O gas mixture. Under different etching conditions, etch rates have been studied. Dry 6 2 etch-induced surface chemical bonding modifications have been systematically investigated using X-ray photoelectron spectroscopy (XPS). Various C-F bonds have been observed as etching products on the etched SiC surface. The increase of bias voltage and etch rate enhance not only the intensity of these C-F bonds but also the relative concentration of covalent C-F bonds on the etched SiC surfaces. Atomic force microscopy (AFM) results indicate that our etching process does not induce roughness on the etched surface even at higher bias voltages.
Reactive Ion Etching of 4H-SiC Using SF6/O2 for MEMS Application
2013
Deep Reactive Ion Etching (DRIE) of 4H-SiC performed using SF6/O2 plasma. The etching rates investigated as a function of the ratio of the O2 flow rate to total gas flow rate under different etching conditions such as the effect of power density, temperature, and the combination of chemistries on etching. The investigation was proven that the contribution and effect of the direct role of Oxygen to deep etching of SiC. An optimum value of O2 fraction of 60% to 40% Sulfur Hexafluoride (SF6) used to give high etching rate of 1.2μm/min. for maximum etching.
Reactive ion etching characterization of a-SiC: H in CF4/O2 plasma
Materials Science and Engineering: B, 1995
In this paper a reactive ion etching process on amorphous silicon carbide (a-SiC) films is characterized by varying the carbon content from 0.73 molar fraction of C (X,. = 0.73) to X~ = 0 (pure a-Si). The film composition was analyzed by electron microprobe analysis. The effect of hydrogen presence in the deposition chamber and of the material doping on the etch rate was considered. The etch rate in a CF4/O e plasma was investigated as a function of the r.f. power and gas pressure in the etching chamber, taking the loading effect also into account.
Reactive ion etching of novel materials—GaN and SiC
Vacuum, 2003
The results of the reactive ion etching of GaN films on sapphire and bulk 4H-SiC in the fluorine containing plasmas are presented. CF 4 /Ar chemistry for etching of GaN as well as CF 4 /Ar and CF 4 /O 2 chemistries for etching of 4H-SiC are used. Etch rates up to B500 (A/min for GaN and B1800 (A/min for 4H-SiC were obtained. The influence of pressure and gas flow rates on the etch rate and surface morphology were investigated. Stylus profilometry was used to measure the etch profiles, whereas AFM and SEM measurements provided us with information on the quality of the etched surfaces. Additionally, SIMS measurements were carried out to determine the influence of ion bombardment on the exposed surfaces and the possibility of their implantation.