Fabrication of hole pattern for position-controlled MOVPE-grown GaN nanorods with highly precise nanoimprint technology

Abstract

Nano Imprint Lithography (NIL) is a promising technology that combines low costs with high throughput for fabrication of sub 100 nm scale features. One of the first application areas in which NIL is used is manufacturing of various types of LED's. The wafers used for producing LED's are typically III/V semiconductor materials grown with epitaxial processes. These types of substrates suffer from growth defects like hexagonal spikes, vpits, waferbowing, atomic steps and surface corrugations on a scale of few 10 μm or even large islands of irregularities. The mentioned irregularities are particularly disturbing when NIL based processes are utilized to create patterns onto the wafer surface. The nanopatterns created by NIL can be applied to control metal organic vapour phase epitaxy (MOVPE) growth of GaN nanorods. This paper will show that NIL is an excellent technology to produce nanopatterned GaN substrates highly suitable to grow defect free arrays of positioncontrolled nanorods for ultrahigh brightness LED applications.