Synthesis and Characterization of Boron Thin Films Using Chemical and Physical Vapor Depositions

Abstract

Boron as thin film material is of relevance for use in modern micro- and nano-fabrication technology. In this research boron thin films are realized by a number of physical and chemical deposition methods, including magnetron sputtering, electron-beam evaporation, plasma enhanced chemical vapor deposition (CVD), thermal/non-plasma CVD, remote plasma CVD and atmospheric pressure CVD. Various physical, mechanical and chemical characteristics of these boron thin films are investigated, i.e., deposition rate, uniformity, roughness, stress, composition, defectivity and chemical resistance. Boron films realized by plasma enhanced chemical vapor deposition (PECVD) are found to be inert for conventional wet chemical etchants and have the lowest amount of defects, which makes this the best candidate to be integrated into the micro-fabrication processes. By varying the deposition parameters in the PECVD process, the influences of plasma power, pressure and precursor inflow on the deposition rate and intrinsic stress are further explored. Utilization of PECVD boron films as hard mask for wet etching is demonstrated by means of patterning followed by selective structuring of the silicon substrate, which shows that PECVD boron thin films can be successfully applied for micro-fabrication.

Free-Standing Porous and Nonporous Polyethylene Thin Films Using Spin Coating: An Alternate to the Extrusion–Stretching Process

“…Coated thin films are typically prepared using chemical vapor deposition, , physical vapor deposition, , dip-coating, − and spin coating, − while free-standing thin films are usually fabricated using extrusion–stretching and spin-coating techniques . A free-standing thin film is defined as a film that does not adhere to a support such as a substrate or a wall surface to maintain a film structure.…”

Sub-ps Pulsed Laser Deposition of Boron Films for Neutron Detector Applications

“…Focusing on physical methods [ 16 ], they possess significant benefits compared to their chemical counterparts. Not only do they require low temperatures, thus facilitating minimum power consumption, but they also avoid the use of expensive and chemically hazardous toxic and/or explosive gases [ 17 , 18 ].…”

“…Moreover, high temperatures are required to improve film adhesion [ 2 , 14 , 18 , 22 ], which, along with low-pressure conditions [ 23 ], is a parameter that affects the structure and density of the deposited films.…”