Advancements in MEMS manufacturing, like many technological markets, is greatly driven by size, cost, and performance. Implementing SOI wafer solutions in the MEMS fabrication process allows production of smaller devices, cheaper costs and higher device performance. Let's take a look at how SOI wafers are created and how they are advancing MEMS manufacturing.

The main draw to SOI (Silicon-on-Insulator) wafer technology is that it features an electrically insulating layer to protect the micro device. They are created using three layers of material. The first layer is the device layer; thin layers of high-quality silicon where the transistors are formed. The second layer is the insulating layer called the BOX (buried oxide) which is usually made out of silicon dioxide. This layer keeps the transistors isolated from the third layer, the handle layer. The handle layer is made of bulk silicone and provides structural support to the device. SOI wafers can be either thick film or thin film, depending on the application.

SMALLER DEVICES

The first advantage SOI solutions have over bulk silicone wafers is that they allow for creation of smaller devices. The wafer manufacturing process makes the transistors more efficient, allowing for the production of more compact chips and greater chip yield per wafer because the chips can actually be placed closer together.

As consumer technology becomes more compact, MEMS companies strive to develop chips that hold more information in a much smaller space. So, in the MEMs world SOI wafer applications are pretty cool, because not only do they allow for smaller designs, they allow for more flexible designs with greater potential.

CHEAPER COSTS

While the initial cost of is more expensive than bulk silicone wafers, the additional features available with SOI actually create lower manufacturing costs for a better, more advanced product. For instance, SOI wafers with pre-etched cavities are available and they simplify the MEMS manufacturing process by lowering development time. SOI wafers also allow production of higher quality chips without the need to purchase and implement more expensive manufacturing equipment.

With an increasing number of MEMS foundries adopting SOI technology and manufacturing processes as a standard, the prices of these wafers have decreased substantially and continue to decrease.

BETTER PERFORMANCE

The final selling point for SOI is that it offers a solution to create superior products. The insulating BOX layer reduces electrical current leakage, which in turn reduces unnecessary power consumption and gives the transistor better performance. It also reduces heat, allowing for these MEMS devices to be used in higher-temperature environments with no ill effects.

The insulating layer also blocks out signal noise which not only allows the transistors' switching speeds to increase, but also results in a more precise product.

As you can see, SOI wafers are advancing MEMS manufacturing in a big way. Many engineering companies as well as Universities use SOI wafers for research, development and testing. Implementing SOI solutions in the manufacturing of silicon wafers allows for smaller, better performing devices with a more diverse range of uses at a better cost for both the manufacturer and purchaser. In this way, SOI wafers are impacting MEMS fabrication in a positive and exciting way, while opening possibilities in new applications.