Development of massively parallel electron beam direct write lithography using active-matrix nanocrystalline-silicon electron emitter arrays

Abstract

Nanoscale lithographic technologies have been intensively studied for the development of the next generation of semiconductor manufacturing practices. While mask-less/direct-write electron beam (EB) lithography methods serve as a candidate for the upcoming 10-nm node approaches and beyond, it remains difficult to achieve an appropriate level of throughput. Several innovative features of the multiple EB system that involve the use of a thermionic source have been proposed. However, a blanking array mechanism is required for the individual control of multiple beamlets whereby each beamlet is deflected onto a blanking object or passed through an array. This paper reviews the recent developments of our application studies on the development of a high-speed massively parallel electron beam direct write (MPEBDW) lithography. The emitter array used in our study includes nanocrystalline-Si (nc-Si) ballistic electron emitters. Electrons are drifted via multiple tunnelling cascade transport and are emitted as hot electrons. The transport mechanism allows one to quickly turn electron beamlets on or off. The emitter array is a micro-electro-mechanical system (MEMS) that is hetero-integrated with a separately fabricated active-matrix-driving complementary metal-oxide semiconductor (CMOS) large-scale integration (LSI) system that controls each emitter individually. The basic function of the LSI was confirmed to receive external writing bitmap data and generate driving signals for turning beamlets on or off. Each emitted beamlet (10 Â 10 μm 2) is converged to 10 Â 10 nm 2 on a target via the reduction electron optic system under development. This paper presents an overview of the system and characteristic evaluations of the nc-Si emitter array. We examine beamlets and their electron emission characteristics via a 1:1 exposure test.

High-performance planar-type electron source based on a graphene-oxide-semiconductor structure

“…In addition, the electron emission efficiency was a constant value of 5 % for more than 42 hours. This current level is higher than the specification of the prototype of the parallel electron beam lithography system (10 A/cm 2 ) [22], which is enough for the several applications of the electron beams although further improvement of the current density is required. The total amount of charge passing through the oxide layer was approximately 160 C/cm 2 without dielectric breakdown of the oxide layer.…”

“…Planar-type electron sources based on a metal-oxide-semiconductor structure (MOS) can be operated at low vacuum, low voltage, and room temperature conditions [14][15][16][17], and 3 emit electron beams with small divergence angles [18]. Although these features are advantageous for the several applications, such as low-cost, high-resolution electron microscopes, highly sensitive image sensors [19], field emission displays [20], and electron beam lithography [21,22], they have a very low electron emission efficiency of 0.002 % [16].…”

Plasmonic Lithography: Recent Progress

“…EBL and FIB are both capable of achieving nanometer scale resolution with high aspect ratio without need for a mask by directly writing with narrow electron/ion beams. However throughput is limited due to the mechanical scanning of the electron/ion beam, space charging effects, and proximity effects, limitations which are not present for plasmonic and evanescent‐field lithography where high throughput at low cost is possible . Nanoimprint employs a mold to be directly pressed into a soft deformable resist material which is then cured via heat or UV illumination.…”

Recent advances in nanorobotic manipulation inside scanning electron microscopes

“…Techniques for constructing nanoscaled devices can be categorized into top-down, bottom-up, and nanomanipulationenabled techniques 3,7 . The top-down approaches typically employ techniques such as X-ray electron beam lithography and nanoimprint lithography [8][9][10] . Bottom-up techniques, such as selfassembly, chemical synthesis or super-molecule techniques 11,12 , are driven by the tendency of physical systems to minimize their potential energy.…”