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MEMSCAP MUMPs technology introduction

The Multi-User MEMS Processes, or MUMPs®, is a well-established program that has run consistently since 1992. Over 80 full process runs have been completed and shipped over that time to hundreds of organizations. MEMSCAP offers three unique stand-alone, multi-mask MEMS processes in MUMPs® : PolyMUMPs, SOIMUMPs, and PiezoMUMPs.


Why Use MUMPs® ?
MUMPs® is low-cost with quick turnaround. The processes are Standard Processes so the properties and layer-to-layer dynamics are well-understood and documented. Using MUMPs® supports the pragmatic design strategy utilized by MEMSCAP's commercial customers, where the designer starts with a fixed process and then creates a design optimized for that process. This approach is superior to a design-first strategy because it leads to fewer design iterations, lower- and fixed-cost development, and less potholes in the road to both functionality and volume production.


How does MUMPs® Work ?
MUMPs® is a shared wafer or multi project wafer service, meaning customers purchase one or more individual die locations(1cm x 1cm size) or tiles on any regularly scheduled run, then create and submit a design based on the process design rules. Eight to 12 weeks later, the customer receives 15 identical chips of their design. To get started, pick a process link above, reserve a die site on a scheduled run, and start designing!

Please see below for more detailed information on each of the processes available through MUMPs®.



PolyMUMPs is the industry's longest-running MEMS multi-project wafer service, with over a decade of history. As the foundation of the MUMPs® program, PolyMUMPs has driven the idea of the Standard Process approach as a clear path to device functionality and volume production. Customers such as Lucent and the former OMM utilized PolyMUMPs very early in the design stage for proof-of-concept prototyping, then modified the process slightly to support the respective applications in volume production.

In the early 1990's, PolyMUMPs was one of the few alternatives available to designers for making MEMS; consequently, the service was primarily used to create innovative devices and resultant Intellectual Property. Today, PolyMUMPs has taken on an much broader role as a process/program that can support a variety of initiatives.

Many universities use the service today as a way to teach beginning MEMS design at the undergraduate level, using PolyMUMPs as the "example" process. In this environment, classes will study MUMPs® during the semester then submit a design and get chips back in time for the end of the semester. Another use for PolyMUMPs is as a benchmarking tool for software models and statistical studies, where theories are validated with measured data from actual, fabricated chips. PolyMUMPs chips also serve as a standard building block for larger scale systems, where the MEMS chip is only one piece of the overall system. PolyMUMPs' well-understood properties and predictable outcomes are advantageously leveraged to make MEMS the "black box" fixed-component.

PolyMUMPs cross section
Figure 1: PolyMUMPs process cross section

About The Process

PolyMUMPs example

PolyMUMPs is a three-layer polysilicon surface and bulk micromachining process, with 2 sacrificial layers and one metal layer. Eight mask levels create 7 physical layers. The minimum feature size in PolyMUMPs is 2um.

Devices that can be made in PolyMUMPs include: Acoustics(microphones), Sensors, Accelerometers, Micro-fluidics, Robotics, and Display Technologies.





SOIMUMPs was introduced to the market in 2003. Unlike PolyMUMPs, the process for SOIMUMPs was an offspring of the MEMSCAP Variable Optical Attenuator product, though the process today has been refined to make it more "multi-user friendly".

About The Process
SOIMUMPs starts with a Silicon-On-Insulator(SOI) wafer, which consists of a stack of handle wafer(fixed 400um), buried oxide, and device wafer. Both 10um and 25um device wafer thicknesses are processed in each lot so the designer has the option of either thickness (designers may also request chips from both thicknesses for additional cost). Using one photolithography step on each side of the SOI wafer, SOIMUMPs allows the designer to pattern and etch both sides of the SOI wafer down to the buried oxide, enabling through-holes to pass light through. Two metal layers, one for bond pads and one for reflectivity, are included in the Standard Process. The minimum feature size in SOIMUMPs is 2um. Devices that can be made in SOIMUMPs include: Gyros, Optical Devices, and Display Technologies.
SOIMUMPs cross section
Figure 2:SOIMUMPs process cross section
SOIMUMPs example



PiezoMUMPs was introduced to the market in 2013 in response to increasing research and interest in Piezoelectric MEMS devices. .

About The Process
The PiezoMUMPs process is based on the SOIMUMPs process with 10um SOI thickness. Its distinguishing feature is a piezoelectric layer of AlN. Top-contact to the piezoelectric layer and the SOI is enabled by means of a patterned layer of Metal. Patterning of the oxide layer that separates the SOI and the AlN allows for contact between the latter. Patterning of the SOI and openings in the handle silicon are available as is the case for SOIMUMPs

Devices that can be made in PiezoMUMPs include: energy harvesters, sensing, ultrasonic transducers, microphones, and actuators.
PiezoMUMPs cross section
Figure 3: PiezoMUMPs process cross section

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