MEMSCAP: MUMPS: Multi-User MEMS processesThe Multi-User MEMS Processes, or MUMPs®, is a well-established, commercial program that provides customers with cost-effective access to MEMS prototyping and a seamless transition into volume manufacturing. MEMSCAP offers three unique stand-alone, multi-mask MEMS processes in MUMPs®: PolyMUMPs, SOIMUMPs, and MetalMUMPs. The MUMPs® program has run consistently since 1992. Nearly 100 process runs have been completed and shipped over that time to hundreds of organizations. One key to the long-running program is the amount of information and reference material readily available to users of the program. MEMSCAP also takes great care to provide timely responses to technical questions and design scenarios. While success is very design-dependent, MEMSCAP aims to provide as much information as possible so the customer can be successful with minimum design iterations. Reference Material is at your fingertips on the www.memscap.com website including a White Paper Bibliography, Design Rules, CAD setup files, element libraries, run measurement data, and Technical FAQs. We also offer a "Beyond the Design Rules" guide for PolyMUMPs, which provides a glimpse of Microsoft Research's experience with the service and how they were successful pushing the limits of the process. 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 To Customize MUMPs®Through MEMSCAP's MUMPs-PLUS! service, customers can choose to modify the Standard Processes by changing thicknesses, sequences, or materials. Though this involves additional cost, MUMPs-PLUS! is still less expensive than Custom Fabrication because the service leverages the regular MUMPs® runs for the steps that are common. For instance, a customer who wanted a thicker Poly2 layer and some backside processing would pay the standard rate for all of the standard steps plus the costs for the additional steps. To facilitate this processing, MEMSCAP sequesters wafers from the lot to be used for those standard steps required by the customer's device. Mask costs are captured as part of the standard die site rate unless the MUMPs-PLUS! order requires additional photolithography levels. How MUMPs® WorksMUMPs 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 below, reserve a die site on a scheduled run, and start designing! PolyMUMPs™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. About The ProcessPolyMUMPs 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™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 ProcessSOIMUMPs 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.
MetalMUMPs™MetalMUMPs was introduced to the market in 2003. As with SOIMUMPs, the process for MetalMUMPs was an offspring of a MEMSCAP product - in this case, a microrelay - though the process today has been refined to make it more "multi-user friendly". About The ProcessMetalMUMPs incorporates all three major MEMS processes: LIGA-like, thick metal electroplating, as well as bulk and surface micromachining. Very tall structures of Nickel, between 18-22um, can be built on top of polysilicon and nitride with a deep, KOH-etched trench underneath. Electroplated nickel is used as the primary structural material and electrical interconnect layer. Doped polysilicon can be used for resistors, additional mechanical structures, and/or cross-over electrical routing. Silicon nitride is used as an electrical isolation layer. Deposited oxide (PSG) is used for the sacrificial layers. The trench layer in the silicon substrate can be incorporated for additional thermal and electrical isolation. Gold overplate can be used to coat the sidewalls of nickel structures with a low contact resistance material. The minimum feature size in MetalMUMPs is 5um. Devices that can be made in MetalMUMPs include: Relays, Microfluidics, Magnetic Switches, and RF Devices.
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