3D TSV: Ready for Manufacturing?

3D TSV: Ready for Manufacturing?

By Yann Guillou, SEMI Europe

In 2012, 3D TSV is one of the hottest technologies, along with 450mm and EUV, in the semiconductor industry due to the technology’s huge potential. Depending on the type of application and timeframe, gains in bandwidth, power reduction, thermal budget, footprint, height, cost and even “time to market” and product portfolio scalability might be expected. In the last five years, major progress has been made. Driven by the application requirements, the technology scope is narrowing and technology options are being eliminated.  A few applications — including Camera Image Sensors (CIS), power amplifiers, memory stacks, memory and logic stacks with a wide and parallel bus interface, and side-by-side integration on a 2.5D interposer— emerged as the drivers. Standards defined through a pre competitive consensus-based agreement have been created by Standard Developing Organizations such as SEMI and Jedec. SEMI recently published SEMI 3D1-0912 - Terminology for Through Silicon via Geometrical Metrology, an important starting point in the move forward volume production. In addition, the recent Yole Developpement report “Equipment and Materials for 3DIC & Wafer Level Packaging,”  forecasts a material market growth from $590 million in 2012 to over $2 billion in 2017 with a 24 percent CAGR. On the Equipment side, the market reached $870 million in 2011 with 28 percent CAGR, still mainly driven by 3D-IC and TSV Interconnect.

Europe: Important Role in 3D TSV Technology

European companies continue to be at the forefront of 3D TSV technology. R&D organizations such as CEA-LETI, Fraunhofer-IZM and imec are among the pioneers to develop state-of-the-art technology to their global partners. On the IDM and foundry side, STMicroelectronics was one of the first companies worldwide to manufacture CIS with via last. Starting with 200mm wafers with a backside via and a conformal copper filling, they quickly evolved to 300mm wafers. Similarly, ams AG industrialized a highly innovative TSV architecture for a demanding medical image sensor solution. These products could be manufactured because the appropriate toolset was available. In effect, equipment and materials suppliers achieved important developments in the last few years; much progress has been made in via etching, isolation and filling, carrier temporary bonding/debonding, wafer backside processing, fine pitch bumping and die stacking. European leaders such as BESI, EV Group, Oerlikon, Suss MicroTec and  SPTS are among the players that invested significant R&D efforts to make this happen. Still, on the road toward high-volume manufacturing, some key challenges remain.

On October 11 during SEMICON Europa 2012, Georg Kimmich from ST-Ericsson reviewed their progress on wide I/O application processors, stating that ST-Ericsson achieved a wide I/O demonstrator product with advanced CMOS technology using via middle type of TSV and Jedec JC42.6 compliant memory interface. However, Kimmich explained that low power wide I/O processors with TSV technology are not currently available on the market and why their introduction was postponed.

WideIO 

Kimmich noted that the reasons are not just technical but linked to a set of different parameters:

  • Business model: A new and complex business model that needs to be defined and agreed upon between partners.
  • Memory evolution: Bandwidth performance of LPDDR3 in a PoP configuration reached an acceptable performance level at better cost. In addition, new memory hierarchy architecture improvement requiring less bandwidth than initially planned was made possible.
  • Thermal constraints: Thermal constraints of wide I/O, due to tight thermal coupling between the processor and the memory die.

However, Kimmich insisted that wide I/O was not a bad idea and that it helps clear the path for technologists to develop the elementary enabling technology “bricks” required for future use in mobile products. He also shared some insights about new smart chipset partitioning that ST-Ericsson is investigating.

New SEMI Event to Convene 3D TSV Leaders

To solve the remaining technical and business challenges that require coordination and cooperation along the supply chain, SEMI is launching a new event to foster a comprehensive analysis of “pain points” with top notch speakers. All the companies and organizations mentioned above will present their latest achievements at a new SEMI event called the European 3D TSV Summit in Grenoble in January 22-23, 2013. At this global event, which will have a strong focus on the manufacturing aspect of 3D TSV technology, the speakers will share their latest company achievements and perspectives. The event will as well feature international leaders from the U.S. and Asia such as Xilinx, Amkor and many more. A broad and deep market overview of 2.5D interposer, 3D-IC and TSV Interconnects will be covered, coordinated by Yole Developpement that will manage a unique market briefing session.

Collective Progress

As 3D TSV technology is now close to volume production, the various stakeholders need to make sure all aspects are covered: design tools and methodology, test solutions from the design and equipment aspect, and inspection and metrology tools developed and evaluated by the customers.

Nevertheless, some technical and business-oriented challenges still remain and need to be collectively tackled. To address them and progress, in addition to the regular plenary talks, the European 3D TSV Summit will allow attendees to interact via a software platform — allowing them to schedule meetings with each other in advance.

Please visit www.semi.org/european3DTSVSummit for registration, exhibition information and sponsorship information. For additional information, contact me (Yann Guillou) at the SEMI Europe Grenoble Office (yguillou@semi.org).

November 6, 2012