Manufacturing of nano-engineered III-N semiconductors: Equipment Business Case

Lead Research Organisation: University of Bath
Department Name: Electronic and Electrical Engineering

Abstract

Tools for defining nanoscale device geometry are widely used in CMOS manufacturing but the economies of scale of Si VLSI do not apply to most other semiconductor industries. Conventional photolithographic techniques are limited by the size of the smallest features that they can pattern so that achieving even smaller features typically requires using the expensive and slow technique of Electron Beam Lithography. As a result only very small regions can be patterned at the highest resolution.

Cost-effective wafer-scale solutions for nanoscale devices do exist but are less widely available. They include Nanoimprint Lithography (NIL), Self-Assembly Lithography (SAL), or more recently Displacement Talbot Lithography (DTL). NIL can achieve sub-10nm features but is very sensitive to particle defects, SAL is cheap but is restricted to limited patterns and domain sizes, and DTL is a new and potentially disruptive technology for applications in the 150-1000 nm range (No DTL systems exist in the UK). The aim of this grant is to bring the two techniques of NIL and DTL more into the mainstream by demonstrating their capability for up-scaling from small area nanopatterned materials or devices into full wafers. The NIL and DTL equipment will allow us to determine the most suitable technique (since either one will not satisfy the requirements for all applications) and related nanofabrication processes creating nano-scale patterns (10-1000 nm) in a range of materials for a variety of applications.

The ability to nanopattern at the wafer scale is essential for commercial production of emerging device types and for research applications where large-area uniformity is necessary for subsequent processing steps. An example of the latter is crystal growth on nanopatterned substrates since large area patterns are essential to achieve good uniformity of growth in the growth reactor.

The ultimate goal behind establishing these nanolithography techniques is to develop advanced fabrication processes for the UK's 21st Century manufacturing industries, and in particular the manufacturing of III-Nitride semiconductor materials. The III-Nitrides are functional materials that underpin the emerging global solid state lighting and power electronics industries. But their properties enable far wider applications: solar energy conversion by photovoltaic effect and water splitting, water purification, sensing by photonic and piezoelectric effects and in non-linear optics. Many applications of these functions of the III-Nitrides are enhanced, even enabled by creating three dimensional (3D) nanostructures. However the exploitation of these properties can only be achieved if there are production-worthy processes available. Hence the purpose of this proposal.

Planned Impact

This proposal is about providing access to wafer-scale nanolithography equipment to a collaboration of internationally leading researchers in the field of III-Nitride semiconductor materials. The III-Nitrides are materials that underpin the emerging global solid state lighting and power electronics industries. Nanostructuring these materials have the potential to enhance their properties and this will be the driving force behind developing the nanolithography capability. These researchers will then make the techniques available to other materials systems and applications as described in the linked research proposal.

Knowledge will be advanced through exploring the capability of DTL for sub-micron patterning and establishing the limits to the technique and how it compares to NIL. The linked research project will involve optical modelling of the DTL process to understand the variety of patterns that can be created.

The capability of large volume manufacturing of nanostructures will accelerate the scientific understanding of the role that they can play in increasing the quality of semiconductor crystals by reducing their defect density and in enabling future device architectures. The importance of this area of research is exemplified by the US administration's recent announcement of $200 million for the foundation of an 'Integrated Photonics Manufacturing Institute'.

The equipment will allow existing proof-of-principle devices that are created by EBL to be up-scaled to pilot production either within the university or commercial sectors. With successful IP protection this could lead to further research contracts in the short term (2-5 years from project start), the creation of a new spin-out company or a new product line within an existing business in the medium term. The wafer-scale processes that will be developed will have economic impact in reducing the costs involved in manufacturing processes.

In particular the programme of research will have direct impact on the industrial partners connected with the proposal. A number of the Research Projects identified in the linked research proposal that will be used to inform and validate the generic manufacturing processes have been inspired through these industrial connections. The work will also impact a wider range of semiconductor companies, including support industries such as the manufacturers of process equipment.

The UK-based expertise and capability will allow new ideas to be brought to market more quickly and cost-savings to be made in the manufacturing process leading to increased competitiveness of the UK semiconductor industry.

Highly-skilled personnel will be trained for future industrial roles on the advanced nanolithography equipment. For University of Bath researchers the training will be delivered via its availability in the cleanroom and external users via the Nanolithography Access scheme. New PhD students in the Condensed Matter CDT will be trained via a 4 day intensive training course covering all the equipment based in the David Bullet Nanofabrication Cleanroom.

Secondary training will be delivered to further researchers through inter- and intra-university seminars enabled by the networks to which the PIs and CIs belong. For example, the UK Nitrides Consortium, the management committee of which the PI serves, exists to allow for formal and informal interactions and the exchange of personnel. In addition, the Open Workshop will educate attendees on the capability of the systems purchased.

There will be long term impact on society through 1) enabling new types of integrated, multifunctional sensors for lab-on-a-chip medical diagnostics and gas sensing, 2) improving the energy efficiency of light emitters to accelerate the shift towards solid state lighting, and 3) developing a UK based semiconductor manufacturing industry that is world leading.

Publications

10 25 50
 
Description This award made available two pieces of large-area nanofabrication equipment at the University of Bath. The programme of work was dominated by the Displacement Talbot Lithography (DTL) equipment rather than Nanoimprint Lithography as the capability of the equipment was found to be much greater. Combined with it being the only system in the UK meant that there was greater interest from non University of Bath researchers.

During the award, we developed a new capability with the equipment ('Double' Displacement Talbot Lithography) that was not envisaged at the application stage that greatly increases the technique's flexibility that would be worthy of further research. Journal papers were published on this, the application of DTL to the nanoengineering of III-nitride semiconductors and understanding DTL in more detail.
Exploitation Route Processes and masks are available for the patterning of large areas of regular nanostructures down to about 150-200 nm on samples up to 100 mm in diameter that can be used in other applications. Both these and the new techniques reported in the scientific literature can be built upon in further research.
Sectors Aerospace, Defence and Marine,Electronics,Energy,Healthcare,Manufacturing, including Industrial Biotechology

 
Title Dataset for "'Double' Displacement Talbot Lithography: fast, wafer-scale, direct-writing of complex periodic nanopatterns" 
Description This study developed a new low-cost nanolithographic tool for creating periodic arrays of complex, nano-motifs, across large areas within minutes. Displacement Talbot Lithography is combined with lateral nanopositioning to enable large-area patterning with the flexibility of a direct-write system. This enables the creation of different periodic patterns in short timescales using a single mask with no mask degradation. The dataset includes images of Matlab models (in .csv format) and SEM experimental pictures of the different experiments realised (discrete lateral illumination, continuous displacements during one illumination). 
Type Of Material Database/Collection of data 
Year Produced 2019 
Provided To Others? Yes  
 
Title Dataset for "Displacement Talbot Lithography: an alternative technique to fabricate nanostructured metamaterials" 
Description This dataset contains scanning electron microscopy (SEM) secondary electron (SE) images of linear gratings resist, dashes and holes in resist that were obtained using Displacement Talbot lithography. These techniques were used to assess the dimensions of the resist features that were obtained with linear grating mask, using single or double exposure steps. SE images also shows the lift-off profile used in order to obtain metamaterial 'fishnet' like metallic structures. The dimensions of the measured linear gratings, dashes and holes are written in text files. 
Type Of Material Database/Collection of data 
Year Produced 2017 
Provided To Others? Yes  
 
Title Dataset for Structural and optical emission uniformity of m-plane InGaN single quantum wells in core-shell nanorods 
Description This dataset contains the results of scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Energy Dispersive X-ray (EDX) measurements carried out on InGaN/GaN core-shell nanostructures. The samples are highly regular arrays of GaN plasma etched cores onto which wide InGaN layer capped with a GaN layer were grown using different metal organic vapour phase epitaxy (MOVPE) growth parameters. Three different growth temperature were used to grow the InGaN layer: 750°C, 700°C and 650°C. SEM images were used to characterize the describe the fabrication, growth and assess nanorod morphologies. TEM were used to investigate the structural properties and assess the InGaN thickness along the entire length of the m-plane facets. EDX measurements were used to assess the homogeneity of the InGaN layer composition at different position along the m-plane facet and on the semi-polar facets. 
Type Of Material Database/Collection of data 
Year Produced 2016 
Provided To Others? Yes  
 
Description Nanopatterned solar cells 
Organisation University of Cambridge
Country United Kingdom 
Sector Academic/University 
PI Contribution Nanopatterned solar cell samples for further processing in Cambridge
Collaborator Contribution Intellectual leadership, design expertise and further processing.
Impact None yet.
Start Year 2019
 
Description Nanostructured UV LEDs 
Organisation Leibniz Association
Department Ferdinand-Braun-Institut
Country Germany 
Sector Academic/University 
PI Contribution The nanostructuring capability developed as part of this grant has been used to create new LED devices for further processing at Ferdinand Braun Institute and Technical University Berlin.
Collaborator Contribution Our partners have used their semiconductor growth infrastructure to grow new structures in order to improve the emission properties.
Impact https://doi.org/10.1016/j.jcrysgro.2019.125343
Start Year 2017
 
Description Nanostructured UV LEDs 
Organisation Technical University Berlin
Country Germany 
Sector Academic/University 
PI Contribution The nanostructuring capability developed as part of this grant has been used to create new LED devices for further processing at Ferdinand Braun Institute and Technical University Berlin.
Collaborator Contribution Our partners have used their semiconductor growth infrastructure to grow new structures in order to improve the emission properties.
Impact https://doi.org/10.1016/j.jcrysgro.2019.125343
Start Year 2017
 
Description Sublimation of gallium nitride 
Organisation National Center for Scientific Research (Centre National de la Recherche Scientifique CNRS)
Country France 
Sector Academic/University 
PI Contribution We prepared nanopatterned samples prepared for further experimentation by the CRHEA-CNRS
Collaborator Contribution CRHEA-CNRS performed sublimation experiments on the samples that we supplied followed by optical characterisation.
Impact https://doi.org/10.7567/1882-0786/ab0d32 https://doi.org/10.1038/s41378-019-0101-2
Start Year 2018
 
Description DWEA: Presentation to CIP 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Industry/Business
Results and Impact A co-investigator visited a major UK photonics organisation to present our new equipment capability and to discuss further collaboration.
Year(s) Of Engagement Activity 2016
 
Description ELB: EV Group pre-conference workshop (2015) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Industry/Business
Results and Impact A member of the research group was invited to present a talk covering our work on nanostructured III-nitride materials at this industrial workshop as a result of our expertise in nanoimprint lithography. Around 30 participants were present from industry and academia throughout Europe. A conversation began at this event with a UK SME around a potential future collaboration. This was pursued following the event and the research group has been awarded an EPSRC Impact Acceleration Account grant to continue the collaboration.
Year(s) Of Engagement Activity 2015
URL http://www.waveoptics.co.uk/
 
Description ELB: Micro & Nano Engineering, The Hague, Sept. 2015 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Poster presentation at this international conference.
Year(s) Of Engagement Activity 2015
URL http://mne2015.org/
 
Description ELB: UKNC Annual Conference 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact Poster presentation outlined the latest results that we have obtained using the new equipment purchased through our EPSRC equipment grant. This generated interest at the meeting and raised awareness of the new capability.
Year(s) Of Engagement Activity 2016
URL http://www.uknc.org/
 
Description PAS: 13th International Conference on Nitride Semiconductors 2019 (ICNS-13), Bellevue, Washington, USA, 7th-12th July 2019 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Talk title: 'Towards electrically injected UV core-shell structure'
Year(s) Of Engagement Activity 2019
 
Description PAS: Poster at 13th International Conference on Nitride Semiconductors 2019 (ICNS-13), Bellevue, Washington, USA, 7th-12th July 2019 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Poster presentation on "Displacement Talbot Lithography for nano-engineering of III-nitride materials"
Year(s) Of Engagement Activity 2019
 
Description PC - Poster presentation at the Micro and Nanoscale Engineering conference (MNE2017) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Poster presentation on the topic of "Understanding the resolution limit of Displacement Talbot Lithography." Useful discussions of the results followed.
Year(s) Of Engagement Activity 2017
URL http://mne2017.org/
 
Description PC - Poster presentation at the Micro and Nanoscale Engineering conference (MNE2018) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Title: Nano-engineering of III-Nitride materials.
Year(s) Of Engagement Activity 2018
URL http://mne2018.org/
 
Description PC - Talk at UK Semiconductor conference, Sheffield, July 2018 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact Talk title: "Double Displacement Talbot Lithography: a new approach periodic nanostructure patterning"
Year(s) Of Engagement Activity 2018
URL https://uksemiconductors.com/?page_id=1516
 
Description PC SPIE Advanced Lithography conference 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Conference presentation
Year(s) Of Engagement Activity 2018
URL http://spie.org/conferences-and-exhibitions/advanced-lithography?SSO=1
 
Description PC: CMP-CDT annual conference, Sept 2019, Bristol 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Postgraduate students
Results and Impact Poster on 'Nano-engineering of III-Nitride materials'
Year(s) Of Engagement Activity 2019
 
Description PC: Talk at META 2019 (July 2019), Portugal 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Talk on 'Large area fabrication of complex periodic nanostructures by 'Double Displacement Talbot Lithography': Fundamentals and applications'
Year(s) Of Engagement Activity 2019
 
Description PMC - China-UK workshop - Sheffield, UK 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Talk title: Nano-engineering of III-Nitride materials
Year(s) Of Engagement Activity 2018
 
Description PMC - Conference talk at the EMN workshop on Epitaxy on MOCVD / Epitaxy on Nanomaterials 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Conference talk on the topic of "Combining top-down etching and MOVPE regrowth: a hybrid approach to nano-engineer III-Nitrides for visible and deep-UV light-emitting devices"
Year(s) Of Engagement Activity 2017
URL http://emnmeeting.org/2018/barcelona/
 
Description PMC - International Workshop on Nitride semiconductors (IWN) 2018 - Kanazawa, Japan 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Talk title: Displacement Talbot Lithography for nano-engineering of III-Nitride materials
Year(s) Of Engagement Activity 2018
 
Description PMC - UK Nitrides Consortium (UKNC) winter conference 2018 - Manchester, UK 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact Talk title: Hybrid top-down/bottom up fabrication of regular arrays of AlN/AlGaN core-shell nanorods for deep-UV emission
Year(s) Of Engagement Activity 2018
 
Description PMC - UK Nitrides Consortium (UKNC) winter conference 2019 - Strathclyde, UK 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact Talk title: Highly-organised selective-area sublimation of GaN nanostructures for directional emission
Year(s) Of Engagement Activity 2019
 
Description PMC - conference talk at the 11th International Symposium on Semiconductor Light Emitting Devices 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Conference talk on the topic of "Hybrid top-down/bottom up fabrication of regular arrays of AlN/AlGaN core-shell nanorods for UV emission" stimulating discussion of the results.
Year(s) Of Engagement Activity 2017
URL http://www.ece.umich.edu/issled2017/
 
Description PMC poster presentation at the 12th International Conference on Nitride Semiconductors 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Poster presentation that allowed discussion of results with interested researchers. Title of poster: "Hybrid top-down/bottom up fabrication of regular arrays of AlN/AlGaN core-shell nanorods for UV emission"
Year(s) Of Engagement Activity 2017
URL https://www.european-mrs.com/meetings/archives/2017/icns-12-12th-international-conference-nitride-se...
 
Description PS - Talk at the SPIE Nanotechnology VIII conference 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Talk entitled "Fabrication and optical properties of InGaN/GaN nanotube for cavity based laser"
Year(s) Of Engagement Activity 2017
URL http://spie.org/conferences-and-exhibitions/past-conferences-and-exhibitions/microtechnologies-2017
 
Description PS - Talk at the SPIE Nanotechnology VIII conference 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Conference talk on the topic of "Displacement Talbot Lithography: an alternative technique to fabricate nanostructured metamaterials".
Year(s) Of Engagement Activity 2017
URL http://spie.org/conferences-and-exhibitions/past-conferences-and-exhibitions/microtechnologies-2017
 
Description PS - poster presentation at the 12th International Conference on Nitride Semiconductors 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Poster presentation to allow discussion of research results: Title of poster: "Design and fabrication of Gallium Nitride grating couplers using Displacement Talbot Lithography"
Year(s) Of Engagement Activity 2017
URL https://www.european-mrs.com/meetings/archives/2017/icns-12-12th-international-conference-nitride-se...
 
Description PS: Nanoscience seminar (Feb 2015) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Postgraduate students
Results and Impact A seminar was given to the Department of Physics Nanoscience group covering the research and equipment covered by these awards. Questions and discussion followed.
Year(s) Of Engagement Activity 2016
URL https://wiki.bath.ac.uk/display/NAN/Nanoseminars