Improving the design of high-voltage switches in both consumer electronics and defense technologies for ships and aircraft, the semiconductor compound gallium oxide (Ga2O3) promises benefits across the electronics industries. However, the capabilities of this ultra-wide band gap compound must first be proven by researchers, such as Dr. Sriram Krishnamoorthy, assistant professor of electrical and computer engineering at the University of Utah.
“A required large-scale research effort is now beginning in the U.S.,” Krishnamoorthy says. “Several universities have teamed up to study the fundamental material science of gallium oxide,” Krishnamoorthy adds.
One limitation for this kind of research is the quality of available Metal Organic Chemical Vapor Deposition (MOCVD) machines, which might not meet requirements to handle gallium oxide properly. While exploring new systems, Krishnamoorthy discovered the Agilis platform from the compound semiconductor research and development company Agnitron.
Since the design process began in 2015, the goal for the Agilis has been to support customizable hardware and control through the Imperium-MOCVD software from Agnitron, but the company recently released a dual-use machine that can grow multiple semiconductor material types. With minor adjustments over a few days, the dual use Agilis can switch from growing beta gallium oxide to III-nitride materials – something no other MOCVD machine can do.
The challenges of creating a dual-use MOCVD platform and refurbishing legacy systems are similar: While cost and reliability are key, the design process begins and ends with modularity. From software to individual components, the machines must easily adapt user requirements, whether that means additional HMI features, increased I/O count, or enhanced processing power. The machine must communicate in real-time with existing systems in a lab or production facility. For Agnitron, this includes enabling development-reactor and showerhead designs for material production and rapid growth rates.
“Supporting these MOCVD processes is key for scaling the technology to make it commercially successful,” Krishnamoorthy explains, adding this was an issue with Molecular Beam Epitaxy (MBE) systems he used previously in research projects.
Reliability in the world of semiconductors means that new components maintain the deposition recipes exactly as the legacy systems did while providing greater dependability, according to Dr. Dmitri Volovik, senior principal engineer for Agnitron.
So, when Agnitron encountered reliability issues with a previous vendor’s automation and control systems, the company was on the verge of losing customers until Volovik began to explore new solutions from Beckhoff Automation.
In an industry where many machines still use separate PLCs and PCs, PC-based controllers were an advantage for Agnitron. With modularity in mind, the Agilis system offers two solutions: The Beckhoff CX2042 Embedded PC with a quad-core, 2.2 GHz Intel Xeon processor and the CX2040 Embedded PC with a quad-core, 2.1 GHz Intel Core i7 processor.
Agnitron Imperium control software uses TwinCAT 3 automation software from Beckhoff and the real-time Windows kernel. The time-critical diagnostic, safety, and process control tasks are executed by the TwinCAT real-time kernel with the tasks assigned to different cores of a multi-core Intel Xeon processor. These tasks continue to execute even if the Imperium software is closed by the user or is interrupted for any reason. The Imperium recipe and routines execution runs outside the Imperium software itself and is controlled by the TwinCAT real-time kernel, as it would be in a typical hardware PLC system.
This approach leads to two product offerings. First is a complete portfolio of OEM MOCVD solutions, designed and manufactured for various materials and processes. Second is a stand-alone upgrade control package for a variety of legacy machines that run outdated and unsupported hardware and software. With combined technologies from Agnitron and Beckhoff, the upgraded controls for legacy equipment support both analog and digital devices simultaneously and provide seamless control software reconfiguration to reflect the upgraded hardware, such as digital mass flow controllers (MFCs), pressure controllers, pressure transducers and pneumatic valve actuators.
Using TwinCAT 3 automation software as the engineering environment and runtime on the Embedded PCs allows Agnitron engineers to write the machine control logic in C# using Microsoft Visual Studio while accessing the TwinCAT runtime and I/O system. As a Windows-based device, the Embedded PC also allows them to install the Imperium control software and save data locally.
The real-time networking capability of EtherCAT provides further benefits for the Agilis. High-density EL3318 EtherCAT Terminals connect Agilis to eight different thermocouples per terminal, which is crucial when working with beta gallium oxide and other complex semiconductor materials. These, along with 16-channel I/O terminals, maintain a compact footprint. Space becomes incredibly tight inside control cabinets, especially on smaller R&D systems.
As with TwinCAT 3, EtherCAT makes it easier to commission units and customize them in the field, and its flexibility to connect with legacy DeviceNet equipment is no small part. EtherCAT has become the leading semiconductor industry network and is a SEMI standard today, but DeviceNet was the industry’s widely accepted standard previously. The EL6752 DeviceNet Master/Slave Terminal creates a bridge between the Beckhoff controller, the EtherCAT network and DeviceNet field devices in customer facilities. Using auto-configuration capabilities, Agnitron engineers can easily connect new and legacy devices over EtherCAT without data loss.
By using one controller rather than a separate PC and PLC, the Agilis machine saves roughly $10,000 on control hardware, not including the substantial reduction in service contract fees that other vendors charge. Also, TwinCAT 3 automation software can be downloaded online for free.
Many refurbishment and retrofit projects also receive this benefit by incorporating the CX2040. However, when existing PLCs are in acceptable working condition, the company will simply replace the legacy PCs with a C5102 rack-mounted Industrial PC (IPC). In either case, the backward-compatibility of Beckhoff hardware and software ensures semiconductor growth recipes are maintained.