Onto Innovation Completes $720M Rigaku Investment to Strengthen Semiconductor Process Control

Onto Innovation Inc. (NYSE: ONTO) has completed the previously announced acquisition of a 27% minority equity stake in Rigaku Holdings Corporation, strengthening a strategic partnership aimed at advancing X-ray-based technologies for semiconductor manufacturing process control.

The investment was acquired from Atom Investment, L.P., an affiliate of Carlyle, for ¥113.078 billion (approximately US$720 million). The transaction marks a significant step in the collaboration between Onto Innovation and Rigaku, which was first announced in April 2026 and focuses on addressing increasingly complex process-control requirements emerging across advanced semiconductor manufacturing.

The two companies are working to advance X-ray technologies for applications where conventional process-control approaches can face limitations, particularly as semiconductor manufacturers adopt more sophisticated device architectures, new materials and increasingly complex manufacturing processes.

Strengthening semiconductor process-control capabilities

The strategic investment comes as semiconductor manufacturers continue to transition towards advanced architectures that require tighter control and more detailed process information. The growing adoption of three-dimensional structures and increasingly diverse material systems is creating new challenges for manufacturers seeking to monitor process performance, identify variations and maintain consistent production yields.

Onto Innovation said its investment in Rigaku is intended to deepen the companies' existing collaboration while accelerating the development of technologies capable of addressing these requirements.

“As semiconductor innovation advances rely increasingly on more complex 3D architectures and exotic materials, our customers face growing challenges in understanding and controlling their most critical manufacturing processes,” said Mike Plisinski, chief executive officer of Onto Innovation.

Plisinski added that the companies have seen early success from their collaboration and that the investment will further strengthen the relationship while supporting faster innovation.

“We are excited by the initial success of our collaboration. This investment strengthens our partnership, accelerates innovation, and enhances our ability to provide more holistic process control solutions to support our customers as they introduce the next generation of semiconductor technologies into high-volume production,” he said.

Focus on advanced manufacturing requirements

The partnership brings together Onto Innovation's expertise in semiconductor process-control solutions with Rigaku's capabilities in X-ray technologies. The companies' collaboration is particularly relevant to semiconductor manufacturers looking for improved visibility into processes involving advanced device structures and materials.

As chipmakers move towards increasingly complex process flows, the ability to characterise materials and structures during manufacturing is becoming an increasingly important component of yield management and process optimisation. X-ray-based technologies can provide additional information for monitoring and analysing semiconductor structures, complementing other metrology and inspection approaches used throughout the manufacturing process.

For Onto Innovation, the investment provides an opportunity to work more closely with Rigaku on technology development and to expand the range of process-control capabilities available to semiconductor customers.

Board representation reinforces strategic relationship

As part of the transaction, Onto Innovation will nominate a director to serve on Rigaku's board. The board representation is expected to provide the companies with a closer framework for strategic collaboration as they continue developing and commercialising solutions for advanced semiconductor manufacturing.

Despite holding a 27% minority stake, Onto Innovation will not consolidate Rigaku's financial results. Instead, the investment will be accounted for under the fair value option method.

The completed transaction follows the companies' April 2026 announcement and represents a deeper commitment to their joint efforts in semiconductor process control.

Supporting next-generation semiconductor production

The investment comes at a time when semiconductor manufacturers are increasing spending on advanced process technologies to support applications including artificial intelligence, high-performance computing and other data-intensive workloads. These applications are driving demand for increasingly sophisticated semiconductor devices, placing greater emphasis on manufacturing precision, process stability and yield optimisation.

As advanced chips incorporate more complex three-dimensional structures and new material combinations, manufacturers require increasingly comprehensive measurement and control capabilities across the production process. Onto Innovation's deeper relationship with Rigaku is intended to help address these evolving requirements by combining complementary technologies and expertise.

The companies' expanded collaboration could therefore play a role in supporting semiconductor manufacturers as they move advanced technologies from development and qualification into high-volume production, where process consistency and yield become critical to commercial success.