We first characterized the etching rate of PS nanosphere and quartz substrate under each individual pure etching gas (CF4/CHF3/SF6/Ar/O2) at a RF power of 40 W and a typical gas pressure of 2 Pa. And then according to the etching results of the above individual gases, we designed several reasonable etching recipes with the mixture of the above gases. It was found that the scale of PS nanosphere was gradually reduced, and therefore, the gap of two adjacent
nanospheres was also gradually increased. The quartz substrate was nanopatterned and kept the same, gradually changing with the gradual change of PS nanosphere mask. To achieving CX-4945 mouse different 3D nanopatterned quartz substrate, the vertical and lateral etching rate should be extremely controlled by varying
the ratio of gas components. As for the hemisphere geometry, the ratio of the lateral and vertical etching rate should be precisely controlled and ranged from 1 to 1.2 with the composition and gas flow of the etching gases as CF4 (26 sccm)/CHF3 (10 sccm)/SF6 (24 sccm)/Ar (5 sccm)/O2 (10 sccm). For the ellipsis geometry, the ratio should range from 1.4 to 1.8 with the MM-102 composition and gas flow of the etching gases as CF4 (26 sccm)/CHF3 (5 sccm)/SF6 (40 sccm)/Ar (5 sccm)/O2 (5 sccm), whereas for the pyramidal pits geometry, the ratio should range from 2 to 2.5 with the composition and gas flow of the etching gases as CF4
(20 sccm)/SF6 (40 sccm)/Ar (5 sccm)/O2 (5 sccm), respectively. Figure 2 shows the results by direct RIE etching with above-discussed mixing gases. Figure 2a illustrates the SEM image of patterned quartz substrate with hemisphere geometry, whose structural parameters are the diameter of 200 nm, the height of sphere coronal of 130 nm, and the nanogaps between two adjacent architectures below 5 nm. It seems that the two adjacent engineered architectures are tangential, with a point contact. Except Dichloromethane dehalogenase the points of tangency, the top morphology was a gradually changed curve. Figure 2b presents a hemi-ellipsis geometry, with structural parameters as sub-axle of 200 nm and height of 130 nm. Figure 2c shows the pyramidal pits with structural parameters as opening of 140 nm and depth of 120 nm. The gap was defined as the distance between the edges of two adjacent architectures on top surface. The side surface of this engineered architecture was flat. So far, much effort to fabricate pyramidal pit geometry was based on wet etching technique-induced large engineered architectures which limited their potential application [30, 31]. Here, we successfully fabricated three different engineered 3D nanostructures with large-area, long-ordered, and controlled morphology by direct dry etching process and NSL technique.
No related posts.