Metrology: Quick and dirty Tevet style

By Rachel Robinson
WaferNews Associate Editor

In the expensive and complicated world of integrated metrology, a different approach could get customers interested in a concept that may work better – while also being cheaper, simpler, and less intimidating.

Tevet Process Control Technologies, Yoknea’m, Israel, is one company trying to provide just such a metrology solution.

After making headlines recently for hiring a new president, Yuval Wasserman, and for raising an undisclosed amount of money in series B financing, Tevet is shifting its status from R&D and product development to market entrance and (soon) growth.

Tevet is hoping to provide “quick and dirty” metrology to end user IC companies and to OEM equipment manufacturers.

Its concept, according to Wasserman, is simple, “Tevet took a fresh look into the need [for integrated metrology] – using a clean slate.”

In a nutshell, the company’s approach relies on broadband relfectometry and using a large spot size.

“If you look at a lot of tools, you have a small spot size to measure thickness,” Wasserman told WaferNews. “Tevet has a large spot size – almost the whole chip.”

He said that the wafer is placed under a measurement head and all the measurements can be done at once. “Because it’s a large spot size, there is no need for pattern recognition, auto-focus, or vision in the system, which therefore reduces costs and increases reliability.”

The Tevet system has multiple sensors; if one wants to measure five points, the system will have five sensors. If one wants to measure nine points, it’ll have nine sensors.

According to Wasserman, measurement is done in three seconds for the whole wafer, allowing it to measure a rotating wafer. Measurement can be done on spin-on dielectric or spinning resist, he added.

Wasserman said that Tevet’s tool could handle transparent films such as CVD depositition or spun-on dielectrics, low-k dielectrics, and photoresist. The system can handle stacks too, he added. It can measure a thickness range of 1,500 to 50,000 angstroms.

“The uniqueness of Tevet’s technology is the fact that by using a large spot size we collect information that allows us to measure the plurality of thickness in the measured area,” Wasserman said. “It means that we don’t have to carefully position a small spot on a chosen area to measure one film thickness and also, it relieves us from the need to utilize vision, pattern recognition, accurate positioning stage, and auto focusing systems thus reducing cost and increasing reliability.”

Wasserman said that Tevet’s competitive edge is that its metrology tool can sit on top of a platform and remotely tally non-invasively and perform measurement without mechanical changes to the platform itself.

He said this is possible by utilizing a window above a wafer handling mechanism and by placing the measurement tool on top of it. “In two beta sites,” Wasserman explained, “we performed beta tests in a fab area where Tevet’s metrology tool was put onto a CVD cluster tool and did the test non-invasively.”

He went on to say that Tevet also tested on another CVD cluster tool where the metrology unit was placed above a cooling station.

Wasserman joined Tevet, which is the Hebrew equivalent for January, from Boxer Cross Inc., where he was senior VP of sales and marketing. He comes into his new role with set goals. Wasserman said that the company is going to add resources to support an initial phase of sales and marketing and then shorten the distance between the company’s development center in Israel and its worldwide customers.

“I envision running the company with two heads, or two legs – R&D in Israel, taking advantage of government incentives and local talent in metrology, while the business [aspects] like sales and marketing will be in the [San Francisco] Bay area, making sure that we address market needs.”



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