High-Speed Platform for Highly Parallel STM Lithography and Hierarchical Assembly

A lack of manufacturing precision has hampered the ability of nanotechnology to live up to its promise of exploiting emerging properties at the nanoscale, thus denying society many energy saving materials and applications. There is therefore a strong need to realize the promise of complex nanosystems by developing atomically precise manufacturing (APM). This project targets a key component of an Atomically Precise Manufacturing system: a high-speed sub-nanometer-precision manufacturing platform for atomic precision patterning and hierarchical assembly. The Scanning Tunneling Microscope (STM) has the requisite patterning precision for APM, but its throughput is inadequate for a manufacturing tool. Our overall objective is to devise a new physical and control implementation of the STM based on Micro-Electrical Mechanical Systems (MEMS) technology for high-speed imaging and high-throughput lithography, which does not suffer from many of the limitations of piezoelectric scanners, first developed in 1982 and largely unchanged. The use of MEMS technology will also enable the possibility of developing an STM with multiple tips scanning simultaneously, so as to scale the overall throughput of a lithography tool for APM. A 1 Degree of Freedom (DOF) MEMS z actuator has been designed and fabricated at UT Dallas. It has been used to take atomic-resolution images in a hybrid STM at Zyvex Labs using the MEMS 1DOF z actuator to maintain the tip height through the tunnel current feedback loop, with a piezo tube performing the xy scanning. This is the first time a MEMS based STM has demonstrated atomic resolution imaging. The z actuator is being combined with a flexure-stage xy scanner to create a high- speed STM, which will be scaled up to multiple tips. Designs for 3DOF xyz MEMS scanners have been completed. What is planned for Phase IIB: (1) Further develop the successful 1DOF z actuator by using a new integrated tip concept from UTD which is an outcome of our DOE 1465 program, allowing for mass production of a commercial product; (2) Commercialize the 1DOF z actuator in collaboration with ScientaOmicron, identifying the advantages of a hybrid STM over a standard STM of interest to microscopy customers, and creating a viable product offering, similar to their QPlus AFM/STM product; (3) Implement the two-tip 1DOF Z actuator with a tilt stage on the flexure stage STM, and demonstrate simultaneous STM imaging with two tips; and (4) Contingent on a viable 3DOF MEMS actuator as an outcome of our 1465 program, we will test their capability for STM. Zyvex, which has a history of commercializing innovative nanotechnology products, will introduce these high-speed, ultra-high precision stages to first address the STM imaging research market at universities, national labs and commercial research companies, and move on to develop research tools for nano-manufacturing development, then metrology and inspection tools for advanced high precision manufacturing, and finally will enable Atomically Precise Manufacturing as a platform both for parallel atomic precision patterning and parallel hierarchical assembly. Atomically Precise Manufacturing will produce unprecedented energy efficient products across a wide range of applications, such as large energy savings from using nanopore membranes in separation processes and quantum computers.