Fabrication of high aspect ratio AFM tips by surfactant added TMAH etching

IF 4.1 3区工程技术 Q2 ENGINEERING, ELECTRICAL & ELECTRONIC

Sensors and Actuators A-physical Pub Date : 2025-03-17 DOI:10.1016/j.sna.2025.116477

Farheen Nasir , Bo Cui

引用次数: 0

Abstract

Atomic Force Microscope (AFM) is an important characterization tool for researchers across various fields. AFM tips are commonly made by anisotropic etching of silicon in alkaline etchant such as potassium hydroxide (KOH), Ethylenediamine pyrocatechol (EDP) or Tetramethylammonium Hydroxide (TMAH). Etching results can be modified using additives, such as alcohol or surfactants, to the alkaline etchant. In this work we use TMAH with two nonionic surfactants, Triton X-100 and Triton X-405, to laterally etch silicon pillars – pre-patterned by dry etching on (111) oriented silicon wafer – to obtain sharp, high aspect ratio AFM tips. We investigate three different mask designs for pillar fabrication. Our results show that the silicon pillars must be at least 30 μm tall before undergoing wet etching in either pure TMAH or surfactant-enhanced TMAH; otherwise, sharp tips do not form. The process achieved a tip aspect ratio as high as 13.8, with an apex diameter as small as 8 nm without oxidation sharpening.

查看原文本刊更多论文

求助全文

约1分钟内获得全文求助全文

来源期刊

Sensors and Actuators A-physical 工程技术-工程：电子与电气

CiteScore

8.10

自引率

6.50%

发文量

630

审稿时长

49 days

期刊介绍： Sensors and Actuators A: Physical brings together multidisciplinary interests in one journal entirely devoted to disseminating information on all aspects of research and development of solid-state devices for transducing physical signals. Sensors and Actuators A: Physical regularly publishes original papers, letters to the Editors and from time to time invited review articles within the following device areas: • Fundamentals and Physics, such as: classification of effects, physical effects, measurement theory, modelling of sensors, measurement standards, measurement errors, units and constants, time and frequency measurement. Modeling papers should bring new modeling techniques to the field and be supported by experimental results. • Materials and their Processing, such as: piezoelectric materials, polymers, metal oxides, III-V and II-VI semiconductors, thick and thin films, optical glass fibres, amorphous, polycrystalline and monocrystalline silicon. • Optoelectronic sensors, such as: photovoltaic diodes, photoconductors, photodiodes, phototransistors, positron-sensitive photodetectors, optoisolators, photodiode arrays, charge-coupled devices, light-emitting diodes, injection lasers and liquid-crystal displays. • Mechanical sensors, such as: metallic, thin-film and semiconductor strain gauges, diffused silicon pressure sensors, silicon accelerometers, solid-state displacement transducers, piezo junction devices, piezoelectric field-effect transducers (PiFETs), tunnel-diode strain sensors, surface acoustic wave devices, silicon micromechanical switches, solid-state flow meters and electronic flow controllers. Etc...