A New Approach to Metrology

The startup Active Layer Parametrics Inc.’s ALPro 50 metrology tool offers “depth profiling of electrical properties at atomic-level resolution” —and automated processing with direct data transfer.

The continuing miniaturization of microchips and nanochips has propelled the use of atomic-layer deposition and atomic-layer etch processes in semiconductor manufacturing. With miniaturization and the use of new materials, the industry needs electrical characterization of semiconductor layers at atomic-scale resolution, done quickly and economically, to enable advanced process development, modeling, and trustworthy manufacturing control.

The ALP metrology tool may be similar to secondary ion mass spectrometry (SIMS) but is unique in providing highly automated measurement of electrical properties within semiconductor levels or layers, said co-founder and CEO Bulent Basol. The ALPro 50 uses differential Hall effect microscopy (DHEM), carried out in three stages.

Abhijeet (AJ) Joshi, ALP’s other co-founder and the chief technology officer, worked with Simon Prussin, who invented the continuous anodic oxidation technique for differential Hall effect measurements, which was a precursor to DHEM.

While ALP’s unique technology will need some time before achieving the widespread use of SIMS, the company is confident that the semiconductor industry will need such technology in working with such materials as silicon, germanium, silicon germanium alloys, and III-V compounds.

“This is a metrology tool and a metrology technology with the capability of depth profiling for electrical properties, including carrier concentration and mobility,” Basol says.

ALP got its start about two years ago, said Basol, as a project that started at UCLA’s labs. It entered the commercialization stage toward the end of 2016. ALP was established, moving to Scotts Valley, Calif., in early 2017. The startup joined the Silicon Catalyst incubator program. Development of the AL50 profiler continued last year, Basol said, culminating with EAG Laboratories placing the first order for the commercial tool. The ALPro 50 was installed at EAG’s facility in Sunnyvale, Calif., in May of 2018 and it is now available for customer wafer measurements.

Bulent Basol, PhD-EE (UCLA), CEO/Co-Founder of Active Layer Parametrics

Basol has more than 30 years of experience in the semiconductor and solar cell industries. The serial entrepreneur was involved in several startups over the years, including International Solar Electric Technology (ISET), NuTool and SoloPower. NuTool was acquired in 2004 by ASM International. Basol holds more than 167 issued U.S. patents and has published 100-plus papers on semiconductor devices, semiconductor processing equipment and thin-film processes.

Basol’s co-founder and chief technology officer, Abhijeet Joshi, has six patent applications pending. Joshi was previously involved in Theia Scientific, a developer of MEMS-based equipment for materials characterization and high-energy light sources. Jalal (Jay) Ashjaee is ALP’s vice president of engineering.

The startup’s board of advisers includes Daniel Armbrust, a co-founder of Silicon Catalyst, along with consultant and entrepreneur Izak Bencuya, marketing consultant John O. Borland and technology visionary Ali Keshavarzi.

“We are a very lean company,” Basol notes. “We are basically engineering. We have seven people, all pretty good people in semiconductors. Manufacturing, testing, and all that, are done outside under our supervision.”

He adds, “It is tough to be a hardware company these days.”

ALP is self-funded with about $1.3 million, along with a National Science Foundation Small Business Innovation Research project grant, said Basol. “We are heavily engaged with several potential customers, doing demos with the largest companies in the industry,” he said. “We are working hard to let people know that such a technique is now available in the marketplace.”

“Now that we have a basic tool with its capabilities, we are mostly working on development of new applications,” Basol notes. “At the present time, we have developed for silicon, germanium, and silicon germanium alloys, that we can do depth profiling to these materials, lightly and easily. More and more, we find ourselves with requests from customers who are interested in III-Vs, especially the nitrides, and very thin polysilicon layers. We see ourselves in early 2019 working on these applications that will really open up the space for the ALPro further. We are negotiating with an overseas customer for a tool sale early next year. We think it will materialize. And then, of course, with the demos, we are trying to show the capability of this tool and its value, to the specific activities, getting customers engaged. So, 2019 will be the year when more people in the industry will hear about this technique and what this tool can do. I don’t have any question that way more applications will pop up. This is like SIMS. We can imagine that this could be a standard like SIMS in the industry…It offers great value to anyone to evaluate electronic devices and for developing processes to grow the semiconductor layers for such applications. 2019 will be exciting for us. We just introduced the tool this year, so many people still are not aware about the capabilities.”

Joshi says, “The main crux of the tool is to provide detailed depth profiles of carrier concentration or the activation levels. When compared with SIMS, we can get a direct measurement of the inactive part of the dopants. And then we collect mobility and resistivity, as well. We are the only tool in the world that can provide this data at sub-nanometer resolutions.”

Basol adds, “When it comes to the size of the company, we’ve intentionally kept it light. We did not make any active investments in manufacturing facilities, or ERP, that kind of thing. All subassemblies, final assembly, and test, are outsourced. We basically provide engineering resources. We ensure service. We have one rep for two of the regions, and we are in negotiation with another rep in Japan. For the U.S., we will take care of it, and we are taking care of it.”