High-speed atomic force microscopy in ultra-precision surface machining and measurement: challenges, solutions and opportunities

Abstract

The atomic force microscope (AFM) possesses a unique capability for three-dimensional, high-resolution imaging down to the atomic level. It operates without the needs of additional requirements on sample material and environment, making it highly valuable for surface measurements. Recent advancements have further transformed AFM into a precision machining tool, thanks to its exceptional force measurement capability and positioning precision. High-speed AFM (HS-AFM) is a specialized branch of AFM that inherits the advantages of high spatial resolution of typical AFM but with significantly improved time resolution down to the sub-second level. In this article, instead of delving into extensive research progress enabled by HS-AFM in the broad fields of biology, biophysics, and materials science, we narrow our focus to the specific applications in the domain of ultra-precision surface machining and measurement. To the best of the authors’ knowledge, a comprehensive and systematic summary of the contributions that HS-AFM brings to this field is still lacking. This gap could potentially result in an underappreciation of its revolutionary capabilities. In light of this, we start from an overview of the primary operating modes of AFM, followed by a detailed analysis of the challenges that impose limitations on operational speed. Building upon these insights, we summarize solutions that enable high-speed operation in AFM. Furthermore, we explore a range of applications where HS-AFM has demonstrated its transformative capabilities. These include tip-based lithography (TBL), high-throughput metrology, and in-line inspection of nanofabrication processes. Lastly, this article discusses future research directions in HS-AFM, with a dedicated focus on propelling it beyond the boundaries of the laboratory and facilitating its widespread adoption in real-world applications.