Is plasma etching the same as dry etching?
The process of dry etching and plasma etching Etching is the process of removing a material from the surface of another material. There are several methods of plasma treatment, but two main types of etching. One is wet etching and the second is dry etching, otherwise known as plasma etching or simply plasma etch.
What is difference between etching and engraving?
The main difference between laser etching and laser engraving is that etching melts the micro surface to create raised marks, whereas engraving removes material to create deep marks. Both processes use high heat to create permanent markings on metal surfaces. Both processes are heavily used for part traceability.
What is physical etching?
In physical etching, ion bombardment through directional momentum transfer causes physical sputtering of atoms. It has the advantage of anisotropic etching, but has the limitation of poor selectivity. Chemical etching involves transport of reactive species through diffusion followed by reaction with the substrate atom.
What is the best hard mask for etching?
Silicon carbide (PECVD SiC), tantalum pentoxide (Ta2O5) and aluminium nitride (AlN) are excellent hard masks for many wet and dry etching processes. Aluminum nitride, however, is easily etched by alkaline solutions such as KOH or even dilute NaOH photoresist developer.
How to find optimum materials for etch mask?
In order to find optimum materials as etch/plating/implant masks, the concept of hard mask has been devised. The mask material is etched with photoresist masking, the photoresist is then stripped and the etch/plating/implant process is performed using the hard mask only.
Why is oxide used as a mask for nitride etching?
The photoresist cannot tolerate such etching conditions. Instead, oxide is used as an etch mask: CVD oxide is deposited on top of nitride, and the oxide is patterned by the photoresist and HF-etched. After resist stripping, the oxide acts as a mask for nitride etching (Figure 11.4).
What is the wet etchant for Si3N4 hard mask?
The hard mask material can be optimized to suit the application, irrespective of the photoresist. The wet etchant for Si3N4 is boiling concentrated phosphoric acid (H3PO4) at 180 °C. The photoresist cannot tolerate such etching conditions.