Substrates & Materials Award Winner
150mm GaN on SiC
Last May IQE launched gallium nitride based; high electron mobility transistor (GaN HEMT) epitaxial wafers on 150mm diameter semi-insulating SiC substrates.
The substrates are supplied by the WBG Materials subsidiary of II-VI Inc.
IQE say that GaN power amplifiers offer superior power capability, efficiency, bandwidth and linearity compared to silicon or GaAs-based technologies. They provide significant benefits in terms of higher performance and lower overall system costs.
GaN-based low-noise amplifiers also exhibit improved robustness, noise figure and dynamic range when compared to incumbent solutions.
In addition, GaN-based transistors can operate at high temperatures, thus reducing system cost, size and weight. As a result, GaN transistors are now established as a leading new technology for a wide range of defence applications.
The 150mm GaN HEMT epi wafer products also enable cost reduction, production capacity and yield improvement, as well as potential for insertion into a wider range of chip fabrication facilities. To date, commercial market penetration of GaN HEMTs has been limited by the higher cost of epitaxial material grown on 100mm SiC substrates.
GaN HEMT fabrication using LDMOS (laterally diffused metal oxide semiconductor) process lines has been demonstrated by IQE's customers and the firm's 150mm products are compatible with existing LDMOS processing lines that have been made available as a result of the silicon industry's transition to 200mm technology.
"For amplifiers serving defense applications, engineers want products built from GaN-on-SiC," says Richard Stevenson, Editor of Compound Semiconductor magazine. "There are concerns over the cost of these wide bandgap materials, but IQE's move to 150 mm products will help to address this."
Compound Semiconductor Manufacturing Award Winners
The PHABLE™ (for "photonics enabler") is a patented technology that is targeted for low-cost fabrication of periodic nanostructures that are mainly needed in photonic applications right now.
PHABLE is a mask based UV photolithography technology, enabling full advantage of existing photo resist and photomask infrastructure. It enables the creation of periodic structures, such as arrays of holes or pillars on a hexagonal or square lattice, or linear gratings over large areas, with high throughput. The unique feature of PHABLE is the very large depth of focus for optical printing. Unlike any conventional proximity, contact or projection lithography technologies, the printed features are independent of the exposure gap over several hundred micrometers. Therefore printing on non-flat surfaces, such as LED wafers, is easily accomplished.
The EVG®PHABLE™ exposure system is the first fully-automated production equipment to feature PHABLE™ ("photonics enabler") technology from Eulitha AG, a pioneer in lithography tools based in Villigen PSI, Switzerland. Integrating Eulitha's full-field exposure technology with EVG's well-established nanolithography production platform provides a unique solution for the automated fabrication of photonic nanostructures. The EVG®PHABLE™ system combines the low cost-of-ownership, ease-of-use and non-contact capabilities of proximity lithography with the sub-micron resolution of lithography steppers to provide low-cost automated fabrication of photonic patterns over large areas. This makes it ideally suited for patterned sapphire substrates (PSS) or to enhance the light extraction (and thus the efficiency) of LED devices. The EVG®PHABLE™ system broadens the micro- and nanopatterning process portfolio, providing a unique, very cost-efficient solution to customers in the LED, optics and photonics markets. The novel equipment clearly demonstrates the synergies of Eulithas and EVGs respective technologies.
The EVG®PHABLE™ system includes a unique Displacement Talbot Lithography approach, enabling to produce features ranging from three microns down to 200 nm with effectively no depth-of-focus limitation or stitching effects that can arise for steppers on substrates with rather poor total thickness variation. Thus, it can be used to pattern substrates up to six inches in diameter in a single exposure step. This approach also enables the EVG®PHABLE™ system to maintain consistently high patterning throughput independent of the wafer size, as well as maintain very large exposure gaps between the mask and wafer, thereby avoiding process-related mask contamination.
The EVG®PHABLE™ system can produce both one-dimensional patterns, such as lines and spaces, as well as two-dimensional patterns, such as hexagonal or square lattices. Thus, it supports a variety of approaches to enhance the light extraction from LEDs. These include LED surface structuring, PSS, photonic crystal applications, nano-wire LEDs and optical gratings. The system can also be configured for photovoltaic, optics or biomedical manufacturing applications.
The EVG® PHABLE™ exposure system is designed specifically for the manufacturing of photonic components. Leveraging EVG's expertise in photolithography, the EVG®PHABLE™ system incorporates a unique, contactless, mask-based lithography approach that enables full-field, high-resolution and cost-efficient micro- and nanopatterning. The unique property of PHABLE is the down to 150 nm printing resolution of regular patterns in a single exposure step. Nonetheless, a mask-substrate separation gap of several tens of micrometers is kept while the image depth can be extended to cover the multiple micrometer thick resist without resolution deterioration. This very high aerial image aspect ratio allows printing of the same high-resolution patterns onto large and highly warped surfaces.
"LED manufacturers are striving to increase device efficiency through improvements in light extraction. The EVG PHABLE can play a key role in their quest," says Richard Stevenson, Editor of Compound Semiconductor magazine.
GENxplor MBE Deposition System
The GENxplor is a revolutionary new molecular beam epitaxy (MBE) deposition system specifically developed to address the needs of university-based compound semiconductor researchers. Starting from a completely new, innovative architectural concept, the GENxplor system records a number of industry firsts.
The GENxplor is the first MBE system of its size to package all elements into a single platform. Combining the growth/process chamber, buffer chamber, load-lock chamber, and the electronics and controls into a single monolithic frame reduces its footprint by 40% compared to similar MBE systems. The flexible system platform is capable of growing on up to 3" wafers with a wider variety of compound semiconductor materials than ever before including: nitrides, arsenides, phosphides, antimonides, oxides, and novel materials such as graphene. In addition, a modular transfer backbone allows the system to be expanded to add other deposition and metrology technologies.
The GENxplor is able to accommodate more configurations than any other MBE system on the market. The process chamber contains new technologies that expand flexibility and capabilities. The first system specifically designed to work with a full complement of bellows-free retractable sources, sources can be maintained, refilled, or changed in isolation from the growth chamber, allowing customers to use the system continuously for years or perhaps even decades without venting. In addition, the single-frame design with cantilevered growth chamber allows users more convenient access and easier maintenance than ever before. Inside the process chamber, water-cooling is integrated to efficiently remove heat from the system. This dramatically reduces liquid nitrogen consumption and lowers the operating cost of the system by thousands of dollars a year. Since its introduction in 2013, the GENxplor is the best-selling MBE system with five systems sold and counting to customers including University of Oklahoma, University of Nottingham, and McGill University.
Today's university-based researchers are under more constraints than ever. Funding is hard to obtain, lab space is at a premium, time is limited, and the materials science requires increasingly sophisticated equipment to push into new frontiers. The GENxplor incorporates technologies to increase uptime by 80% or more, reduce footprint by 40%, reduce operating costs by thousands of dollars a year, incorporate other deposition or metrology techniques, and increase usability and improve serviceability compared to competitive systems – all at a reduced capital cost.
The GENxplor is the first fully-integrated 3" MBE system designed into a single frame, reducing the footprint by 40%. The only system designed for use with a full complement of bellows-free retractable sources, the GENxplor can be operated in ways never seen before by retracting and isolating sources from the growth chamber, increasing uptime. Additionally, differential source pumping allows users to grow in regimes never before possible. Use of water-cooling throughout the system reduces the need for liquid nitrogen, saving money. Finally, the novel construction with a cantilevered growth chamber provides customers with unparalleled access for usability and serviceability.
Veeco is the only company to develop a 3" MBE system fully-integrated into a single platform. The concept of combining the MBE hardware with the electronics and controls to reduce footprint while improving accessibility and serviceability is unique within the industry. Similar MBE systems on the market have three separate modules (MBE hardware, electronics cabinet, and software control computer) with hardware and cabling running along the floor connecting them. Veeco is also the only MBE vendor to offer retractable sources – Knudsen cells that are able to be used at normal working distance from the substrate, retracted behind a gate valve while maintaining electrical connections, and then isolated from the growth chamber for refill and maintenance, all without the use of a bellows (which are prone to failure, potentially resulting in a catastrophic vent of the chamber).
"I believe that many readers voted for the GENxplor because they understand that university researchers are looking for a tool that is robust, relatively small, and capable of allowing them to carry out their research as quickly and successfully as possible," says Richard Stevenson, Editor of Compound Semiconductor magazine.
Metrology, Test and Measurement Award Winners
8500 Series THz System for Material Characterization
The Lake Shore 8500 Series THz System for Material Characterization is a measurement platform that provides the materials development community with a fully integrated solution for exploring THz frequency electronic, magnetic, and chemical properties of materials in cryogenic and magnetic field environments. The system features a coherent, variable frequency continuous wave (CW) THz spectrometer from EMCORE and specially designed THz emitter and detector components which offers high spectral resolution THz-transmission measurements of materials in these extreme environments. Integrated software operates the temperature controller, helium level monitor, superconducting magnet supply, and spectrometer for automated turn-key experimental control.
In the quest to develop high-speed computing, storage, imaging, and communications applications, novel and existing electronic and magnetic materials with favourable high frequency material properties will need to be identified and characterized. The Lake Shore 8500 Series THz System addresses the challenge of the development community seeking to explore the THz-frequency properties of bulk and thin film semiconductors, organic electronics and oxides. Cryogenic temperatures and high magnetic fields are used to tune the THz-frequency response in order to help elucidate the physical mechanisms underlying the material's electronic or magnetic properties. What's more, the continuous-wave THz source offers a more cost effective approach, compared to the more conventional time-domain THz (TDS) spectroscopy, for THz materials characterization. The fully integrated Lake Shore THz system is offered at a cost-point comparable to a stand-alone pulsed-laser source. Also important: The system provides a solution for researchers who do not have the means to build a custom THz characterization system and who lack off-the-shelf software for management and analysis of their experiments. Going into the development of the system, one of Lake Shore's primary objectives was to develop software that was easy to use. The company knew this would be key to how well the system is adopted by the materials development industry – particularly scientists and engineers who do not consider themselves terahertz experts.
Conventionally, low-temperature, high field THz measurements would be performed by placing a sample in the beam path of an optical cryostat and then painstakingly align the terahertz source and detector onto the sample. Lake Shore, in close collaboration with EMCORE, developed robust THz emitter and detector components that have proven to operate quite well at liquid helium temperatures and in magnetic fields up to 9 T. In the 8500 Series THz system, fiber-coupled THz source and detector are mounted within the cryogenic environment and in proximity to the sample. Custom designed optical stages maintain good optical alignment of the THz devices over temperature and multiple thermal cycles. The Lake Shore system uses CW measurements to enable variable temperature measurements of electronic and magnetic materials in two distinct sample types — semiconducting wafers (like InSb or InP) and thin conductive films supported by an insulating substrate (like ZnO/sapphire, graphene on silicon, or 2DEGs). By replacing terahertz time domain technology with less costly, higher resolution CW spectroscopy, instrumentation cost can be reduced by 50 to 75%, opening the technology to a much broader market. What's more, these capabilities are provided in a completely integrated platform that has the software to conduct proceduralized experimental methods and reliably analyse the spectral results.
"This terahertz analysis system is a valuable edition to the toolkit of every engineer and researcher looking to uncover the properties of their semiconductor materials," says Richard Stevenson, Editor of Compound Semiconductor magazine.
Device Design and Packaging Award Winner
45mm SiC Six-Pack Power Module
Cree's CCS050M12CM2 is the industry's first commercially available silicon carbide (SiC) six-pack power module in an industry standard 45mm package. When replacing a silicon module with equivalent ratings, Cree's six-pack module can reduce power losses by 75 percent, which leads to an immediate 70 percent reduction in the size of the heat sink or a 50 percent increase in power density.
The new six-pack SiC module unlocks the traditional design constraints associated with power density, efficiency, and cost, allowing designers to create high performance, reliable, and low cost power conversion systems.
When compared to state-of-the-art silicon modules, the SiC 1.2 kV, 50A modules deliver performance equivalent to silicon modules rated at 150A. The efficient switching of the SiC module also allows for significantly less derating than silicon IGBTs. This enables significantly higher frequency operation, which both increases fundamental output frequency and reduces passive component size in applications like motor drives, solar inverters, uninterruptible power supplies, and industrial power supplies. Even when designers simply substitute Si modules with SiC in motor drive applications, the improved performance of SiC reduces power losses, leading to reduced cooling requirements and, in turn, to a reduction in size, weight, complexity, and the overall cost of the power electronics system.
The CCS050M12CM2 six-pack modules from Cree are the industry's first commercially available silicon carbide (SiC) six-pack power module in an industry standard 45mm package and are available for immediate shipping through Digi-Key Corporation and Mouser Electronics.
"Gains in efficiency in the power electronics sector are more valuable than ever before," says Richard Stevenson, Editor of Compound Semiconductor magazine. "Cree is one of the pioneers, helping to save energy with its SiC power modules."
Innovation Award Winner
Direct Drive for CoolSiC
Infineon's CoolSiC transistor is a normally on JFET device, combining the well known low ohmic performance of high voltage SiC transistors with an extraordinary level of ruggedness since no susceptive gate oxide with questions about interface quality and lifetime is used in the component. However, the device is normally on and thus, a way to make it familiar with system requirements must be identified. For comparable wide band gap devices like earlier JFETs or today's normally on GaN HEMTs the traditional cascode arrangement is used. This simple concept offers by a series connection of the normally on component with a normally off low voltage silicon MOSFET (the blocking voltage of the MOSFET must exceed the voltage required to block the device) and connecting the gate of the normally on transistor with the source of the MOSFET. The concept can be easily derived from the equivalent circuit of each DMOS today.
However, this concept has some disadvantages like potential dynamic avalanche stress on the MOSFET or limited controllability of the switching slopes. Thus, a modified setup was developed at Infineon, sill being based on the series connection of the two devices, but now controlling each gate separately. To enable an easy implementation a driver IC was developed to operate the setup. In this mode, the switching is no longer performed via the MOSFET gate, but directly via the JFET. The MOSFET is passive in this configuration and just acts as a safety switch for start up or failure mode in which the original cascode idea is maintained. The concept is called Direct Drive.
The idea deals with the challenge of operating a normally on device safely under modern system aspects and securing lowest losses at the same time. It addresses as well ruggedness problems of competing solutions and requirements from the application with respect to the dv/dt control in PWM operation.
The idea extends the original cascode idea in a way that their negative points are diminished. By disconnecting the gate contact of the normally on JFET from the MOSFET source we can access the main switching devices directly for easy dv/dt control. Furthermore, the MOSFET is no longer switched in each dynamic cycle and thus, no additional MOSFET losses have to be considered. Finally, the MOSFET is not driven in each cycle into avalanche what increases the ruggedness of this circuit.
The novelty of the concept is the extended cascode concept into a direct drive mode which offers a lot of additional advantages and lowest losses combined with high operational stability. Since the control philosophy is integrated into a corresponding driver IC the efforts on the user side is minimized, they can operate the device as they are familiar with from earlier power switches, but taking full advantage from the outstanding performance.
"Infineon's engineers have come up with a clever way of getting the best out of their normally on JFET, while giving customers the characteristics that they cherish," says Richard Stevenson, Editor of Compound Semiconductor magazine.
R & D Award Winner
In 2013 IMEC, a nano-electronics research centre successfully demonstrated the first III-V compound semiconductor FinFET devices integrated epitaxially on 300mm silicon wafers, through a silicon fin replacement process.
The achievement illustrated progress toward 300mm and future 450mm high-volume wafer manufacturing of advanced heterogeneous CMOS devices, monolithically integrating high-density compound semiconductors on silicon.
The breakthrough enables continual CMOS scaling down to 7nm and below, and also enables new heterogeneous system opportunities in hybrid CMOS-RF and CMOS-optoelectronics.
IMEC believe this is the world's first functioning CMOS compatible III-V FinFET device processed on 300mm wafers an accomplishment which demonstrates the technology as a viable next-generation alternative for the current state-of-the-art Si-based FinFET technology in high volume production.
The proliferation of smart mobile devices and the ever growing user expectations for bandwidth and connectivity will drive the continual need for software and hardware advancements that extend from networks to data servers and mobile gadgets. At the core of the hardware will be new process technologies that allow for more power-efficient CMOS transistors and increased integration, enabling a higher level of functionality.
This prompts process technologies that enable heterogeneous devices spanning operating ranges for targeted circuits, maximizing the system performance.
During the last decade, transistor scaling has been marked by leaps in process technologies to provide performance and power improvements. The replacement of poly-silicon gate by high-k metal-gate in 45nm CMOS technology represented a major inflection in new material integration for the transistor. The ability to combine scaled non-silicon and silicon devices might be the next dramatic transistor next step ending the all-silicon reign over digital CMOS.
This work could represent an important enabling step.
At the finest grain, co-integration of high-density heterogeneous transistors has been challenged by the ability to combine disparate materials and structures while maintaining low enough complexity and defectivity.
IMEC's breakthrough process selectively replaces silicon fins with indium gallium arsenide (InGaAs) and indium phospide (InP), accommodating close to eight percent of atomic lattice mismatch. The technique is based on aspect-ratio trapping of crystal defects, trench structure, and epitaxial process innovations. The resulting III-V integrated on silicon FinFET device shows an excellent performance.
IMEC's research into next-generation FinFETs is performed as part of IMEC's core CMOS program, in cooperation with IMEC's key partners including Intel, Samsung, TSMC, Globalfoundries, Micron, SK Hynix, Toshiba, Panasonic, Sony, Qualcomm, Altera, Fujitsu, nVidia, and Xilinx.
"Silicon CMOS is finally running out of steam, and higher mobility materials hold the key to maintaining the march of Moore's Law," says Richard Stevenson, Editor of Compound Semiconductor magazine. "Introducing these new materials will not be easy, but the approach that imec has developed is very promising."