Linton Crystal Technologies (LCT) announces the release of software that will enhance automated melt gap management in the crystal growing process. This is the first of several planned enhancements to LCT’s Kayex Intelligent Crystal Control System (KICCS™). KICCS provides hardware and software process control for the Czochralski (CZ) process crystal growers Linton manufactures.

The ability to consistently maintain the melt gap is critical to growing a quality crystal. Though a laser-based system for measuring the melt gap was available in the past, LCT no longer makes it available for purchase.

“Our new software uses multiple techniques and more robust data, gathered from a high-resolution camera and other machine parameters, to automate the management of the melt gap during a single crystal-growing cycle, as well as across subsequent cycles,” explains Jeromy Tompkins, senior software engineer for Linton Crystal Technologies.

Among the key benefits of the software are:

• Melt gap control in all growth states (i.e. neck, crown, shoulder, body, and tail)
• Reproducible melt gap from crystal to crystal
• Table-driven melt position for ramping the melt gap from one position to another
• Automatic calculation of CL/SL ratio based on crucible and crystal geometries
• Failsafe fallback to calculated CL/SL ratio if auxiliary melt level inputs fail

This software underwent testing at Linton’s Research and Development Center in Dalian, China, as well as various customer sites. It was used during multiple crystal-growth cycles, each of which placed different demands on the melt gap control system.

“It was very successful at managing the gap; tests repeatedly demonstrated the software’s functionality,” says Tompkins. “Feedback from our field service engineers and clients during testing also helped us identify additional improvements that would make grower operators more comfortable with the control and improve the melt gap process.”

Among the enhancements made after testing is the ability for the operator to alter the melt-level calibration during a run to respond to changing conditions.

The software can control the measured melt gap to a precision of 0.5 mm when holding it steady.

Linton Crystal Technologies is the world leader in the design, development and manufacture of CZ furnaces for producing monocrystalline ingots for the semiconductor, machined part and solar industries. The company specializes in silicon and produces equipment for materials such as germanium and gallium arsenide and InSb. They also provide diamond wire saws and specialized equipment for shaping and polishing ingots and cutting them into wafers. Additionally, LCT offers the technical and process engineering support and replacement parts to help clients get businesses off the ground, improve productivity and continue to innovate.

For more information about Linton Crystal Technologies, visit www.lintoncrystal.com.