SOI wafers – Silicon-On-Insulator line

Produced with 20 years of expertise Okmetic’s comprehensive line of bonded Silicon On Insulator (SOI) wafers provides an optimal platform for the manufacture of demanding MEMS and sensor applications and power and RF devices. Okmetic SOI wafers enable additional design freedom, maximum device performance, cost-effectiveness and ease of manufacturing.   

Okmetic was among the first silicon wafer suppliers to introduce Silicon On Insulator technology and SOI wafers to MEMS industry, and now the company has been volume producing SOI wafers for 20 years already. SOI wafers are silicon wafers with a thin silicon film on insulating oxide, and their production requires a very high level of technical expertise. SOI wafers enable the manufacture of the most advanced MEMS, power and RF components used in automotive and healthcare applications, smart wristbands, smartphones and tablets as well as applications related to Internet of Things (IoT) utilizing sensor-provided data in device-to-device communication.

SOI wafers provide an optimal platform for the manufacture of MEMS
and sensor applications and power and RF devices

Okmetic’s Silicon on Insulator (SOI) wafers are manufactured by bonding technology. Two silicon wafers are bonded together leaving an insulating oxide layer between them. Typically, sensing elements and IC applications are built on the top device layer. The buried oxide layer is an excellent electric insulating layer and an effective etch-stop, but can also act as a sacrificial layer. The bottom handle wafer is supporting the structure, but can also be utilized in sealing the structure or as part of the sensing element or the component.

Comprehensive line of Silicon on Insulator (SOI) products

Okmetic’s SOI wafers are manufactured entirely in-house which allows us to monitor all the critical crystal and wafer parameters to ensure the highest quality SOI wafers. The widest wafer portfolio on the market enables the selection of e.g. optimal electrical conductivity and different crystallographic orientations to ensure better utilization of the anisotropic properties of silicon. Our sales and technical support are happy to help finding an optimal solution, customized for your needs. 

Okmetic’s SOI wafer line consist of the following products:

Typical SOI wafer specifications

Growth method
Cz, MCz, A-MCz®
150, 200 mm
Crystal orientation
<100>, <110>, <111>
N type dopants
phosphorus, red phosphorus
P type dopants
<1mOhm-cm up to over 7,000 Ohm-cm
Device layer thickness

From 1 μm to > 200 μm
Tolerance ±0.5 μm (standard BSOI), ±0.3 μm (0.3 SOI),
0.1 μm (E-SOI®),  ±0.7 μm (C-SOI®)

Buried oxide layer thickness
From 0.3 μm to 4 μm, typically between 0.5 μm and
2 μm
Type: thermal oxide
Handle wafer thickness From 300 μm to 950 μm, typically 725 μm in 200mm wafer and 380 μm in 150mm
Back surface polished or etched

Okmetic – Technology leader in Silicon On Insulator wafers

Okmetic is a true pioneer in the field of Silicon On Insulator SOI wafers as the company started to develop SOI technology for the MEMS industry already in the 1990’s and has been volume producing SOI wafers ever since 2001. The MEMS industry was the first to adopt the new Silicon On Insulator wafer technology and it continues to be the main growth driver for SOI wafer demand. Over the years, SOI wafers have also expanded to power management solutions utilizing trench isolation technologies such as high voltage BCD and lateral HV devices. SOI wafers also used in the RF field for the needs of which Okmetic has designed High Resistivity BSOI wafers.

2021 Okmetic SOI 20th anniversary

2020 EC-SOI combining E-SOI® and C-SOI®benefits

2019 New C-SOI® production line in 2019

2016 Launch of E-SOI®

2015 SOI wafers for power management

2010 Extremely small pressure sensors and wearable electronics

2009 C-SOI® in volume production

2008 SOI-based silicon microphones

2006 C-SOI® -based inertial sensors for automotive industry

2005 First C-SOI® deliveries

2001 SOI wafer production line started

1998 Okmetic SOI technology established