Manufacturing of nano-engineered III-nitride semiconductors

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

Abstract

The goal of this proposal is to develop advanced fabrication processes for Gallium Nitride (GaN) and related materials (AlN and InN), collectively the III-Nitrides, for the 21st Century manufacturing industries. 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. As such, the particular focus of the proposed research is to develop and nanostructuring processes on a manufacturing scale and to unlock the potential of these properties of the III-Nitride semiconductors in a range of innovative materials and devices.

The research will address and resolve 1) the need of industry to be able to scale-up laboratory-based results based on individual piece or wafer fragments to batches of wafers of up to 6 inches in diameter, 2) the need to be able to design devices that are robust with the manufacturing tolerances, and 3) the need to rapidly characterise the devices to increase packaging yield. Potential commercial exploitation of the manufacturing processes and innovative materials and devices will be aided and led by the applicants' company partners.

The programme of research opens with developing the core capability of wafer-scale (up to 6 inch) nanopatterning by nanoimprint lithography and the newly developed technique of Displacement Talbot Lithography, a potentially disruptive technology for generating nanostructures. These lithographic techniques will then be integrated with additive and subtractive processes to form 3D nanostructures across whole wafers. In a major application, the developed nanofabrication techniques will be used in developing manufacturing processes for the growth by metal organic vapour phase epitaxy (MOVPE) of non-polar and semi-polar GaN templates to address the persistent problem of the quantum confined Stark effect limiting the efficiency of light emitting diodes (LEDs) and GaN based laser diodes. The computer aided design method known as Designing Centering will be developed for process optimisation to maximise the yield of nanostructured devices (initially LEDs). Another activity will be to explore the use of electron beam and optical techniques, which are capable of characterising materials and devices on the deeply sub-micron scale, as production tools for screening materials and part-processed devices.

The combination of wafer-scale nanofabrication techniques, advanced MOVPE growth, characterisation methods and Design Centering will then be deployed in the design and manufacture of innovative and emerging devices including core-shell structures for LEDs and photovoltaic applications, and nano-beam sensors that incorporate photonic crystals.

Having established the core capability for the III-Nitrides, it will be extended to nanostructuring other semiconductors, notably InP and related materials as used in the manufacture of devices for optical fibre telecommunications.

Planned Impact

This proposal is about developing manufacturing processes that will allow the properties of the III-Nitride semiconductor materials to be exploited within semiconductor devices. Fundamentally it addresses devices in which nanostructuring offers improvements to device performance, either via higher quality material or enabling new types of device. It focusses on 1) the need of industry to be able to scale-up laboratory-based results based on individual piece or wafer fragments to batches of wafers of up to 6" in diameter, 2) the need to be able to design devices that are robust with the manufacturing tolerances, and 3) the need to rapidly characterise the devices to increase packaging yield.

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 Case for Support 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.

Commercialisation of the technology generated in this proposal, which is not covered by the Lambert-style agreements that will be established with the industrial partners, will be achieved by protecting any key intellectual property and know-how through patents and non-disclosure agreements, and using these to attract further research contracts and income in the short term (2-5 years from project start). The work could lead to the creation of a new spin-out company or a new product line within an existing business in the medium term. The necessary Consortium Agreement will be put in place at the start of the project, with a view to promoting impact and industrial engagement.

Highly-skilled personnel will be trained for future industrial roles, partly via industrial secondments with our project partners. Primarily the training will be directed at the RAs and research students connected with the project, but 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 a number of the PIs serve, exists to allow for formal and informal interactions and the exchange of personnel.

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.
 
Description CTC: Lecture Series in India as part of 'Science and Beyond' organised by the British Council, 10th-20th January 2016. 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Lecture Series in India as part of 'Science and Beyond' organised by the British Council, 10th-20th January 2016 by Dr Carol Trager Cowan.
Gave talks to researchers, postgraduate and undergraduate students, teachers, trainee teachers and members of the public across India on - 'Studying structure and light emission in the scanning electron microscope&amp' and 'Engaging the Public with Science and Technology - from statues to rainbows'.
See for example:
https://www.britishcouncil.in/events/science-and-beyond-public-talks-carol-trager-cowan
http://www.iiserpune.ac.in/userfiles/files/Carol%20Trager-Cowan%281%29.pdf
http://www.thehindu.com/features/metroplus/bowled-over-by-science/article8123927.ece
Year(s) Of Engagement Activity 2016
URL http://www.iiserpune.ac.in/userfiles/files/Carol%20Trager-Cowan%281%29.pdf
 
Description CTC: Lecture at the Birla Industrial and Technological Museum (BITM), Kolkata, India, January 2015 'Nitrides - The Rainbow Material'. 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Schools
Results and Impact Lecture at the Birla Industrial and Technological Museum (BITM), Kolkata, India, January 2015 'Nitrides - The Rainbow Material' by Dr Carol Trager-Cowan.
Year(s) Of Engagement Activity 2016
URL http://timesofindia.indiatimes.com/city/kolkata/British-Council-brings-UK-science-speakers-to-Kolkat...
 
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 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