What is the advantage of using wire tips?
Conventional AFM probe tips are made in three main types: silicon, silicon with metal coatings, and deposited metal in the shape of a tip. Each of these types of tips have serious drawbacks when used for contact node probing. Silicon is an unsuitable material for making contact to nodes, forming a schottkey diode in place of ohmic contact, which distorts measurements and should not be used in conducting high-frequency or low-current signals. During scanning and contacting, tips naturally experience some wear. However, metal coatings on silicon tips wear off too quickly and leave an intrinsic diode at the contacting tip. Deposited metal tips are typically made with materials that are unable to contact hard metals like tungsten vias. Unlike the other three alternatives, tungsten wire tips are extremely hard and have been used successfully for years to probe all electronic materials. There are no junction or ohmic contact issues and the tips will not interfere with sensitive or high-frequ
