Soitec Bernin II 300mm SOI (Silicon on Insulator)

Silicon on insulator wafer maker Soitec has expanded manufacturing at its company’s headquarters in Bernin (France) with a 300mm line. The Bernin II facility will bring the company’s annual capacity to above 2 million (200mm equivalent) wafers.

SOI is widely expected to become the standard process on the way towards the 45nm node. It divides microprocessor powers by a factor of three or four, while also increasing speeds. SOI wafers are still relatively expensive, but this extra cost is compensated by process cost reduction on the side of the IC makers. The more the industry moves towards small geometries, the greater are SOI’s advantages.

Target applications include high speed and low power electronic systems such as telecoms, automotive, computing, aerospace, medical, optoelectronics and consumer equipment. The process is becoming essential for high performance microprocessors, smart power devices, opto-electronic circuits, MEMs and miniature LCD and high resolution displays.

SMART CUT WAFERS

The SOI layer electronically insulates the top (active) silicon layer from the rest of the wafer.

Soitec’s proprietary Smart Cut process transfers ultra thin silicon layers onto another surface. A thermal activation process works as an “atomic scalpel,” slicing the wafer horizontally to transfer a thin layer of silicon from the donor substrate and place it onto a new substrate (a single substrate can be reused many times for further layer transfers). Thicknesses can range from 20 nanometers up to several microns for the top silicon, and buried oxides can also be from below 100 nanometers up to a few microns thick.

Soitec makes 100mm, 125mm, 150mm, 200mm and now 300mm wafers. The 300mm wafers are important to components like microprocessors, which tend to have larger die sizes. Bernin II has taken delivery of a complete 300mm tool set with ion implantation, bonding, CMP (chemical mechanical planarization) and metrology tools. 12 production lines have a capacity of 1.2 million wafer starts per year and that figure could increase with the installation of higher throughput equipment. The expansion comes after Soitec’s first production plant, Bernin I, hit full capacity in 2002.

The company provides a range of thin film substrates for IC manufacturing, including bonded SOI (tradenamed UNIBOND) and silicon on quartz (SOQ) wafers. Soitec is also developing UNIBOND SOI for RF telecoms.

R&D LOOKS AT SILICON RELATED MATERIALS

Industry analysts anticipate that 300mm SOI wafers will make up 50% of all wafers taken by the industry by the year 2009. Besides its own production, Soitec has strategically cross licensed its technology to companies like Shin-Etsu Handotai. Soitec is also expanding operations in several countries with new distributorships. It has for example made Seika Corporation its exclusive distributor in China, aiming to capitalize on the number of fabs being built there.

Soitec has recently augmented its R&D partnership with LETI (Grenoble, France), one of Europe’s largest applied electronics research laboratories. Soitec has gained exclusive rights to LETI’s intellectual property related Smart Cut technology for new materials, including full sublicensing rights to the technology. The two organizations have a longstanding relationship and Soitec intends to develop new products with the Institute.

R&D activity will be conducted in the new Bernin fab as well as in LETI facilities. The Bernin R&D facility features a Class 1, 8in cleanroom totalling approximately 600m². Bernin research will focus on developing strained SOI and silicon on quartz (SOQ) substrates, which will be developed with Soitec licensee Seiko Epson. Soitec is also extending Smart Cut to new silicon related materials like silicon carbide, silicon germanium, sapphire and III-V materials.

80% WORLD SHARE OF SOI WAFERS

Created in 1992 by two researchers from CEA-LETI (one of Europe’s largest microelectronics research institutes), Soitec now has a greater than 80% world share of SOI wafers. Clients include 20 major semiconductor manufacturers including AMD, Motorola, Mitsubishi Electric and OKI.