Aerosol deposition-based micropatterning of barium titanate via sulphur hexafluoride inductively coupled plasma etching

• The micropatterning of AD deposited BTO films by ICP etching method is first studied.
• A lateral resolution down to approximately 500 nm is yielded.
• The state-of-the-art etching rate of 67.5 nm/min is obtained.
• Authors represent an attractive micropatterning method for processing ferroelectric materials.

Aerosol deposition (AD) is an advantageous alternative to the conventional thin film deposition method and thermal spray coating technology; this process is a very attractive method for micropatterning barium titanate (BTO) materials. AD features a high deposition rate, low process temperatures, fine patterning for miniaturisation, and improved device performance for many applications, such as RF components, dynamic random access memory, micro-electro-mechanical systems, and optical devices. In this study, BTO micropatterns deposited by AD are combined with inductively coupled plasma (ICP) etching technology in SF6/O2/Ar plasmas to yield a lateral resolution reaching approximately 500 nm, which is at least 10 times smaller than the resolutions achieved by other recent deposition technologies. The experimental results indicate that adding the appropriate quantities of O2 and Ar to SF6 can improve the etching properties by increasing the etching rate of BTO films while decreasing the surface roughness of the Pt layers. The maximum etching rate is 67.5 nm/min when the SF6/O2/Ar composition is 75/5/10 sccm, which is 15 times faster than the conventional plasma etching process. In this study, the micropatterning of AD-deposited BTO films is systematically investigated and analysed while using sulphur hexafluoride ICP etching.