Advancing E Beam Lithography
1) You recently announced an enhanced layout beamer for direct write E Beam, could you please explain what this is?
The Layout BEAMER is taking care of all required operations to get the layout from the designed device to production of the structures by an e-beam writer system. This includes the so called "datapreparation"; importing the layout, extracting layers, cells or regions to be printed, tone-reversal depending on the resist type, biasing to correct for optimum CD, Boolean operation to combine the device layout with supporting structures like alignment marks and other operations to modify the layout. The second important operation is the "process correction." The layout does not print on the wafer as designed because of material effect (e.g. scattering of the electrons penetrating the resist and the underlying layers) and process effects (e.g. the development of the exposed resist). The layout BEAMER provides the tools to model and correct these process effects (e.g. Proximity Effect Correction). The third process is to transfer the corrected layout data into the "language" (format) of the electron beam writing system. This process is called "fracturing". Each e-beam system has its own format depending on its writing strategy. The quality of the "fracturing will influence the quality and speed of e-beam writing.
2) What industry challenges have arisen to require such a solution?
Technical:
E-Beam lithography is increasing in importance for R&D, prototyping and small volume production because there is no need to produce a mask first (mask-less lithography) and e-beam lithography can produce extremely small dimensions down to the 10nm range. This saves development time and cost. Therefore e-beam lithography is moving from a "research" environment into a more "production"-like environment. This has also changed the user group from a highly qualified research user to the production engineer. This requires new solutions for handling of processes, automation and quality control for the process from the layout to the printed wafer result on the e-beam system. Layout BEAMER offers an integrated, flexible and easy to use platform, allowing design and saving of custom processes and process automation.
Increasing device complexity and decreasing dimensions result in advanced process modelling and correction (like OPC in optical lithography) capability. The Layout BEAMER has integrated process simulation, verification and optimization functions. The energy deposition during e-beam write and the resulting resist contour on the wafer can be simulated. Analysis runs with varying parameters to help optimize layout and process.
Commercial:
Dedicated suppliers for software solutions for ebeam lithography have disappeared from the market. This resulted into poor customer responsiveness coupled with the high pricing of the software available to direct write users. GenISys is providing a fast, flexible and responsive service specific to this application.
3) What are the potential applications of Layout BEAMER 2.0?
Any application of e-beam direct write:
- micro-electronics, micro-optics, MEMS, nanostructures
4) Does the Layout BEAMER assist manufacturers from design through to manufacture? Please explain?
Yes it does, for the part of e-beam lithography. It optimizes design / layout enabling high-level manufacturing. It provides the tools for modeling, verification, design correction and amendments / processes and processes to achieve best device performance.
5) Design layout is an extremely complex process that generates a large amount of data for manufacturers. How does this software assist with the volume of information and what type of user interface is offered?
The Layout BEAMER can import and export the layout in the most commonly used formats (GDSII, DXF, CIF,…) and formats of major e-beam systems. The kernel is a high performance layout data base which is able to access huge layouts of unlimited size (e.g several 10 GB, even 100GB). The layout size is not limited by the system memory. The intelligent geometrical sorting of the high performance database enables an extremely fast access (in a few seconds) to areas of a huge layout. This is one of the core competencies of GenISys and is also the base of Layout ENGINE, a layout handling tool kit we deliver to manufacturers of large inspection and mask repair systems (e.g. the Merit system of Zeiss) to enable "dye to database" operation.
The user interface is our VisualFLOW GUI for flexible and easy (drag&drop) flexible design of complex hirarchical processes. The database driven, modular, process flow oriented concept combines performance and user-friendliness. The capability to save "user flows" and the capability of using variables and loops support automation and quality control. Most important is that all needed functions such as highly efficient import of large layout data, rich postprocessing functions, latest technology proximity effect correction and an efficient viewer for inspection are integrated on one platform. The user does not have to combine several tools and write complicated scripts, which result often in errors.
6) Does the Layout BEAMER have to work with specific tools or is it usable with a variety of manufacturers?
The Layout BEAMER already supports all major e-beam systems. GenISys is open to provide the formats and interfaces to specific tools on
customer request.
7) Manufacturers are seeking ways to automate their processes to reduce costs and contamination potential. Does the BEAMER assist with this?
Yes, this is a strength of the Layout BEAMER. It is equipped with the capability to save "custom process flows" in a database and re-use them. The customer can build a corporate database with their specific processes. They are available as "push-button" solutions. This enables automation so that the design processes can be used by operators. Most importantly, it helps avoid false process settings, which may result in loosing production time. It saves on time and cost to enter the processes with completed scripts.
8) Your guidelines suggest that the software is useful in proximity effect correction. This is becoming a key factor for manufacturers. Can you please explain what impact your software has on proximity effect correction?
We have implemented a high performance PEC using advanced algorithms. The algorithms ensure that the feature edges get maximum dosage, resulting in optimum CD-control of lines and gaps. With Version 2.0 we can import calculated or experimentally measured proximity functions and use it for the correction. This enables not only correction for electron scattering effect, but also for process correction.
9) How can the use of this software assist the manufacturer in future design and manufacturing?
Layout BEAMER provides users of ebeam lithography a solution for efficient development and prototyping. This shortens development time and enables the development of future designs.
10) What impact does the software have on mask costs?
Layout BEAMER is focused on the ebeam direct write at present.
11) Can you provide examples of who is using the software already and the feedback they have provided?
Dr. Andre Van der Hart, Director of e-Beam Lithography in the Process Technology Department of the Institute of Bio- & Nano-Systems at Research Centre Jülich-Germany advises that, "from a technical point of view, data prep and in particular process correction tools are often poorly integrated and difficult to use. Layout BEAMER provides a fast, flexible and highly efficient framework for our e-Beam data prep needs, "With its intuitive usage and flexibility that supports multiple layouts and machine formats, Layout BEAMER is a versatile data prep resource – and is suprisingly fast and easy to implement."
12) What markets do you expect to benefit from the software?
Research, development and prototyping of advanced ICs, integrated optics, nanostructures
13) Where do you see E-Beams future role in manufacturing?
e-Beam lithography is becoming the method of choice in the development and prototyping phase of new nodes. It is needed for device design and processes for mass production. e-Beam is also a candidate of "Next Generation Lithography" for manufacturing of <32nm node.
It is complimentary to EUV for smaller volume production. Because of the limited throughput, it will be used for most critical layers and most probably integrated with higher productivity, optical lithography methods.
e.Beam lithography will inevitably arrive at a standard production method for special devices requiring very small dimensions (nano structures) and/or precision (optical devices). E-Beam lithography is already used for production of master imprint lithography, high security holograms or high precision optical scales.
