Plasma etching properties of various transparent ceramics

Remarkable plasma-resistance performance by nanocrystalline Y2O3·MgO composite ceramics for semiconductor industry applications

“…Unlike the result of a medium level of mass loss, MgAl 2 O 4 showed the deepest etching depth at all etching times. This tendency was noted to be similar to the earlier work 26 www.nature.com/scientificreports/ of single-crystal sapphire 20,32 , while a previous report by the authors using pore-free transparent Y 2 O 3 found best-ever results with a record low 20% etching depth compared to that of sapphire 26 . It is surprising that the developed YM showed an even lower etching depth compared to that of transparent-grade Y 2 O 3 , which will be discussed later with the results of microstructural analysis of the etched surface morphology.…”

“…3(c) reveal that the etched surface of YM was extremely smooth (R a = 2.3 nm). Min et al demonstrated that the surface roughness levels of transparent Y 2 O 3 , MgAl 2 O 4 and sapphire were 9.0, 10.3 and 27.0 nm, respectively, under etching conditions identical to those in this study 26 . Kim et al reported that the surface flatness during plasma etching played a critical role in reducing the generation of particles; it was noted that either the particles remained inside the chamber or were pumped www.nature.com/scientificreports/ out 21 .…”

“…Generally, the surface roughness of conventional ceramics after plasma etching is reported to have a large range, from 100 nm to several microns, and these results have mainly been attributed to residual pores in the ceramics 4,8,20 . For transparent ceramics having nearly pore-free microstructures, smooth erosion (plateau-like surface morphology) was found to be possible without selective erosion caused by ion bombardment around the pores 4,25,26 . Given that the R a value of the as-polished surface was under 2 nm, the AFM images in Fig.…”

“…A comparative study with the pore-free transparent Y 2 O 3 and MgAl 2 O 4 ceramics bas been carried out. In our previous report 26 , various transparent ceramics free from light-scattering pores, which also act as the origin and/or as a magnifier of the etching reaction, were proven to exhibit plasma resistance exceeding that of single-crystal sapphire. The nanostructured YM research has been pursued to its excellent mid-wavelength IR transmittance and reliable mechanical properties for use as hypersonic infrared windows, domes and eye-safe laser [27][28][29][30][31] .…”

Optimization of a TEOS addition on plasma resistance of YAG ceramics

“…As is well known, Y 2 O 3 has excellent etching resistance in fluorine‐containing plasma; however, its range of application is limited owing to its poor sintering performance and high production cost. Researchers have found that the plasma resistance of yttrium aluminum garnet (YAG) ceramics is close to that of Y 2 O 3 and much higher than that of Al 2 O 3 and SiO 2 9–13 . Kim et al 10 .…”