This Small Business Innovation Research (SBIR) Phase I project will develop a new approach for the fabrication of periodic nanoelectronic device arrays. Processing of structures on the sub-100nm scale poses significant challenges due to limited resolution of available lithographic methods. The proposed technique will address the deficiencies of the existing nanofabrication approaches by directly growing nanostructures inside a molecularly self-assembled NanoWell shadow mask, which offers an unprecedented atomic-scale control over the nanostructure size. During the proposed research, a silica shadow mask with cylindrical pores ~3-30 nm, or NanoWells, will be self-assembled employing organic surfactant molecules. Silicon nanorods will be grown inside NanoWells by both CVD and sputtering, followed by chemical removal of a shadow mask. An array of Si nanorod LEDs will be fabricated to demonstrate the feasibility of the proposed approach as well as the quantum size effect for the Si nanorods. If successful, this cost effective, high-throughput, and ultra-high precision technique will figure into a wide range of electronic device array applications such as sensors, processors, memories and displays, and provide enhanced miniaturization, speed, and power reduction. The proposed technique will offer the dramatically improved nanoprocessing capabilities for the fabrication of flat panel displays, sensor arrays, quantum dots, nanomagnetics, image and signal processors. It will have a broad range of potential applications in commercial microelectronics and image processing industries.