C-SOI® wafers – Cavity SOI – Okmetic

Okmetic C-SOI® is a bonded Cavity Silicon On Insulator wafer, which has built-in sealed cavity patterning etched on the underside deal with wafer or on the buried oxide (BOX) layer earlier than bonding and thinning the highest silicon wafer appearing as a tool layer. Okmetic can provide wafers which have buyer alignment marks on prime of the system layer to convey data on actual cavity location. This ensures clean integration of Okmetic and buyer processes. The cavities are used to simplify system manufacturing and they are often built-in into the energetic, passive or structural components of the system. This makes it doable to course of extra complicated and developed buildings than could be doable with the usual BSOI wafers. The cavities will also be used for integrations of IC and MEMS processes additional growing the utilization potentialities. Okmetic manufactures these wafers according to equivalent high quality and cleanliness requirements as normal bulk silicon wafers.

C-SOI® wafers are extra than simply wafers, in reality they are often higher described as partially constructed sensors or digital parts as their superior expertise allows extra streamlined MEMS manufacturing course of. That is one motive why their utilization as a platform for MEMS and sensor gadgets has surged quickly in the course of the previous few years after regular development in the course of the previous decade.

Required membrane thickness varies throughout functions

Okmetic’s high-technology cavity SOI course of allows the manufacture of extraordinarily skinny and thick membranes, which expands the number of system design and processing potentialities. Okmetic Cavity SOI wafers with skinny membranes are extensively used e.g. for strain sensors, silicon audio system and ultrasonic transducers like PMUT and CMUT’s. Cavity SOI wafers with thicker membranes provide vital advantages for gadgets akin to inertial sensors (gyroscopes, accelerometers, IMUs), micromirrors and different optical gadgets (like optical switches and many others.). Relying on the design, both skinny or thick membranes can be utilized for microfluidic gadgets like inkjet heads, timing gadgets and different resonators and IC and MEMS course of integrations. As well as, SOI wafers utilization can be increasing into RF gadgets, for the wants of which Okmetic has developed Excessive Resistivity BSOI and C-SOI® wafers.

C-SOI® specs

The tables under give some tips on Okmetic C-SOI® wafer specs. Our C-SOI® wafers are all the time custom-made options, so please contact our gross sales and technical help for extra detailed data.

System layer specs

Buried oxide (BOX) specs

Deal with wafer specs

Cavity specs

Entrance floor alignment marks

C-SOI® wafers optimize MEMS manufacturing course of

C-SOI® wafers have many advantages in comparison with bulk silicon micro-machining and even conventional SOI expertise: more cost effective and streamlined MEMS manufacturing course of and extra complicated, superior and better-performing gadgets.

C-SOI® wafer is a complicated resolution with a number of advantages:

• Diminished system dimension and value
• Superior system efficiency and precision
• Elevated system reliability
• Extra superior system designs
• Optimized system manufacturing course of ensuing to decrease prices and sooner time to market

Extra superior designs and superior efficiency and precision

Okmetic’s patterning and etching course of has best-in-class etching uniformity. Okmetic’s skill to supply C-SOI® wafers with extraordinarily skinny and thick membranes, well-defined horizontal dimensions and suppleness to regulate the hole between launched construction and the substrate allow manufacture of extra superior system designs. Cavity SOI wafers additionally allow the optimization of effectivity and electrical properties by way of minimization of parasitic capacitances. As well as, course of optimization benefits could be gained by way of built-in bottom packaging and airtight sealing.

Personalized Cavity SOI options with shorter cycle time and higher high quality

C-SOI® wafers are custom-made to match buyer system design and course of seamlessly. Buyer system design is taken into consideration all through the manufacturing course of, ranging from the crystal development part.

Okmetic has been producing Cavity SOI wafers since 2005. Okmetic’s patterning and DRIE cavity etching is a completely in-house course of, which reduces the Cavity SOI wafer cycle time considerably as there isn’t a have to ship wafers to prospects for cavity etching after which again to Okmetic for bonding. However most significantly, this sort of holistic strategy to C-SOI® wafer design and processing has elevated the standard and reliability of wafers and helped optimize the MEMS manufacturing course of. Learn extra about Okmetic’s patterning and cavity etching course of and wafer tailoring.

Value-effectiveness over bulk silicon MEMS and conventional SOI expertise

C-SOI® wafers provide extraordinarily cost-effective resolution over bulk silicon micromachining and even BSOI wafers. For instance, when manufacturing a strain sensor on 400 µm thick wafer the fee per chip could be lowered by 50% in comparison with bulk silicon micromachining and 25% in comparison with BSOI wafers. It’s because the patterning, etching and bonding prices are included within the C-SOI® wafer worth and the system dimension is smaller when utilizing the extra superior C-SOI® wafer platform.

C-SOI® variations for specialised wants

EC-SOI wafer

Okmetic EC-SOI combines state-of-the-art silicon applied sciences akin to extremely uniform E-SOI® wafer with embedded cavity buildings of C-SOI® wafer. EC-SOI wafer is a brand new sort of enabling substrate, which opens up new potentialities for superior MEMS gadgets akin to silicon photonic built-in circuits (PICs) and ultrasonic transducers, with PMUTs and CMUTs.

Double C-SOI® wafer

Okmetic Double C-SOI® wafer combines two system and buried oxide layers with cavities on deal with wafer. This mixture has proven so as to add worth for MEMS and photonics gadgets.

C-SOI® wafer with patterned system layer

C-SOI® wafer’s cavities are patterned on the system layer as an alternative of the deal with wafer. Learn extra about our patterning course of.

C-SOI® wafer with poly through

C-SOI® wafer with by way of Buried Oxide through kind electrical non-isolated contact between system and deal with wafer. This can be utilized for system layer grounding.