New MEMS manufacturing approaches pave way to smaller, more cost-effective devices!

LYONS, FRANCE: In 2011, simplification of manufacturing remains an objective: Yole Développement’s MEMS law “One product, one process, one package” still rules. Will it still rule in 2020?

To give clues to answer these questions, Yole Développement released its report, MEMS Manufacturing & Packaging. This report analyzes the main MEMS manufacturing evolution.

“With this report, our aim is to provide understanding of current challenges of MEMS manufacturing, packaging & materials. For each MEMS manufacturing step, bottlenecks and challenges are highlighted”, explained Dr. Eric Mounier, project nanager at Yole Développement.Source: Yole Développement, France.

Yole Développement’s approach is to analyze the MEMS industry evolution, per MEMS devices (inertial MEMS, magnetometers, pressure sensors). Technical & market data covers the period 2000 - 2020. This study includes cost analysis, technical trends, impact on MEMS equipment and materials, manufacturing tools (DRIE, sacrificial release) and engineered wafers and materials.

Although MEMS technologies have not been driven by the same size demands as ICs, it doesn’t mean that MEMS manufacturing is just standing still. The fast growing MEMS markets, now driven by consumer applications, are:

Size driven: for demanding consumer applications like smart phones and laptops.

Performance driven: for high end applications like aerospace.

Cost-driven: for high volume applications like cell phones, automotive and game consoles.

New MEMS manufacturing, packaging technologies and specific materials are necessary for solving these issues. Yole Développement’s report highlights the future challenges for MEMS production and packaging. From bulk micromachining to surface micromachining and then to SOI, MEMS technology has been following a well-defined evolutionary technical roadmap with 3D integration being the next possible step.

In the report, you will find manufacturing trends for the different MEMS devices in terms of processes, new packaging approaches, 3D integration, CMOS MEMS integration, new materials such as structured wafers, …

This report analyzes the following MEMS processes at different levels:
At substrate level: engineered SOI, glass, thin wafers.

At front end level: piezo materials, getters, bonding, resists, CMOS MEMS, release stiction, DRIE, singulation, lithography, etching, sacrificial release, CAD tools.

At packaging level: thin film packaging, active capping, pixel-level packaging, through glass vias, through Si vias.

Technology platforms: TSV, hermetic WLP, interposer, standard packaging, MUMPS process, testing.

What will be the future of MEMS manufacturing?
This report analyzes the current major MEMS manufacturing trends and presents some clues for understanding the next evolution in terms of die size, cost, packaging.

Among other MEMS technologies to watch for the future, we have identified: at the substrate level: SOI, glass, thin wafers; at MEMS die level: getters, fusion bonding, release stiction, singulation, CMOS MEMS, DRIE, trench isolation; and, at packaging level: TGV, TSV, pixel-level packaging, thin film capping, active capping…
For all the analyzed MEMS technologies, wafer forecasts 2009-2015 by type of step (DRIE, wafer bonding, sacrificial etch, through Si vias, thin films packaging, CMOS MEMS, thin wafers) are estimated.

DRIE and wafer bonders are the technologies subject to major evolution: “Main reason is that both technologies are increasingly used for 3D TSV in the mainstream semiconductor business. Wafer bonding is the direct competitor for CMOS MEMS approach”, says Dr Eric Mounier. For example, microbolometer players are more and more considering wafer bonding approach to stack the MEMS to the ROIC wafer.

CMOS MEMS is likely to be restricted to very specific applications where MEMS arrays will need very close electronic processing. For all other case, it will depend on MEMS product cycle time, flexibility, cost, integration, market demand and power consumption.

In 2011, simplification of manufacturing remains an objective: Yole Développement’s MEMS law “One product, one process, one package” still rules. Will it still rule in 2020? The current work on technology and product platforms attempts to overcome Yole Développement’s MEMS law. But this approach will be custom-made standard processes.

By 2020, it is likely that MEMS fabs will have developed internal standard process blocks but it will be fab-specific standard tools. The technology/product platforms currently proposed by some MEMS foundries is an interesting approach. Technology platforms can be used to create their own product platform once a product is designed into a technology platform.