Multiple electron-beam lithography (original) (raw)
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Electron optical column for a multicolumn, multibeam direct-write electron beam lithography system
Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, 2000
Electron beam direct-write lithography systems are capable of meeting the resolution requirements of all future ITRS nodes and have a significant cost of ownership advantage over masked technologies, but these systems typically have very poor throughput due to space charge limitations. Ion Diagnostics has developed a multicolumn, multibeam (MϫM™) direct-write system that circumvents the space charge limitations by spreading the electron current over the wafer. The resulting lithography system can achieve critical dimensions of less than 100 nm with production throughputs greater than 60 wafers per hour, independent of wafer size. In this article we describe the electron optical column used in this system. We have developed a novel, microfabricated electron gun that produces 32 parallel electron beams that are individually controlled and blanked and contain deflectors that allow the gun optics to act as a perfect lens. Each column is 2 cm ϫ2 cm and can align and scan the 32 beams in parallel on the wafer. The wafer voltage is typically held at 50-100 kV, and backscattered electrons are collected for imaging and alignment information. Theoretical results and some performance results for a prototype column are presented.
Electron multi-beam technology for mask and wafer writing at 0.1nm address grid
IMS Nanofabrication realized a 50 keV electron multibeam proof-of-concept (POC) tool confirming writing principles with 0.1 nm address grid and lithography performance capability. The POC system achieves the predicted 5 nm 1 sigma blur across the 82 μm × 82 μm array of 512 × 512 (262,144) programmable 20 nm beams. 24-nm half pitch (HP) has been demonstrated and complex patterns have been written in scanning stripe exposure mode. The first production worthy system for the 11-nm HP mask node is scheduled for 2014 (Alpha), 2015 (Beta), and first-generation high-volume manufacturing multibeam mask writer (MBMW) tools in 2016. In these MBMW systems the max beam current through the column is 1 μA. The new architecture has also the potential for 1× mask (master template) writing. Substantial further developments are needed for maskless e-beam direct write (EBDW) applications as a beam current of >2 mA is needed to achieve 100 wafer per hour industrial targets for 300 mm wafer size. Necessary productivity enhancements of more than three orders of magnitude are only possible by shrinking the multibeam optics such that 50 to 100 subcolumns can be placed on the area of a 300 mm wafer and by clustering 10 to 20 multicolumn tools. An overview of current EBDW efforts is provided.
Direct-write Electron Beam Lithography: History and State of the Art
MRS Proceedings, 1999
Direct-write electron beam lithography is a patterning technique that has rapidly evolved over the last 40 years. For many years it has been possible to use electrons to pattern lines with widths as narrow as 10 rum. Recent advances in resist materials, electron sources, and system integration have further enhanced the capabilities. High-sensitivity resists provide substantial increases in the throughput without sacrificing resolution. Thermal field-emission sources improve the stability and reduce the minimum attainable spot size. Modem lithography systems integrate the electron beam column with advanced control electronics, making a system capable of nanometer-scale placement accuracy. In addition to these improvements, the technology is more accessible now than ever before, thanks to the proliferation of lithography systems consisting of modified scanning electron microscopes.
Low Voltage Electron Beam Lithography
1992
Center for Integrated Systems, JUN 2 1993 Stanford UniversityUD ' IIIi 1i IJII 11111 h~tli Jl IiI~ 11l)111 Stanford, Ca 94305. C The contract has three parts covering aspects of high precision electron beam lithography. (1) Comprehensive computer modeling of the electron beam tool. (2) Experimental determination of the properties of sources, columns, and targets, and (3) The use of silicon single crystals as straightness and orthogonality standards using orientation dependent etching techniques.
A simple electron-beam lithography system
Ultramicroscopy, 2005
A large number of applications of electron-beam lithography (EBL) systems in nanotechnology have been demonstrated in recent years. In this paper we present a simple and general-purpose EBL system constructed by insertion of an electrostatic deflector plate system at the electron-beam exit of the column of a scanning electron microscope (SEM). The system can easily be mounted on most standard SEM systems. The tested setup allows an area of up to about 50 Â 50 mm to be scanned, if the upper limit for acceptable reduction of the SEM resolution is set to 10 nm. We demonstrate how the EBL system can be used to write three-dimensional nanostructures by electron-beam deposition. r
25th European Mask and Lithography Conference, 2009
Electron beam direct write lithography is known for its high resolution capabilities, which enables studies ahead of the technology in production. That is why this technique is used for many years in laboratories for R&D. Recently it was shown that electron beam lithography can be integrated within the flows of the microelectronics industry for prototyping applications, low volume production and to support optical lithography for ASIC manufacturing. Moreover recent lithography workshops highlighted that the multi beam solution is identified as one potential technique for next generation lithography techniques to meet the requirements of sub-32nm technological nodes. The present proximity correction methods for electron beam lithography are based on the standard dose modulation principle. However these methods cannot properly ensure a sufficient control of the patterning of the most critical designs. To push the resolution capability of electron beam lithography, a new correction method is proposed. It consists in a multiple pass exposure strategy. For example instead of patterning a line in one pass (standard exposure), the pattern is split in several basic blocks with potential overlaps exposed in several passes and with an adapted dose. Compared to standard exposure, this solution provides an improved process window and a better control of the critical dimensions. We could achieve energy latitude of 22.2% and we improved the line edge roughness by 27% on 45nm dense lines (line width equal to space) with this method.
REBL: A novel approach to high speed maskless electron beam direct write lithography
Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena, 2009
The system concepts used in a novel approach for a high throughput maskless lithography system called reflective electron beam lithography (REBL) are described. The system is specifically targeting five to seven wafer levels per hour throughput on average at the 45nm node, with extendibility to the 32nm node and beyond. REBL incorporates a number of novel technologies to generate and expose lithographic patterns at estimated throughputs considerably higher than electron beam lithography has been able to achieve as yet. A patented reflective electron optic concept enables the unique approach utilized for the digital pattern generator (DPG). The DPG is a complementary metal oxide semiconductor application specific integrated circuit chip with an array of small, independently controllable metallic cells or pixels, which act as an array of electron mirrors. In this way, the system is capable of generating the pattern to be written using massively parallel exposure by ∼1×106 beams at ext...