Material Properties and Applications of Silicon (Si)
Silicon is the 14th element on the Periodic Table. Crystalline silicon substrate is available as a wafer in multiple sizes from 1-inch to 450 mm.
• Band Gap : 1.12 (eV)
• Electron Mobility : 1,400 (cm2/Vs)
• Electrical Resistivity : 2.3×103 Ω·m (at 20°C)
• Thermal Conductivity : 149 W/(m·K)
Semiconductor industry has been developed along with mass-production, price reduction and quality stability improvement of silicon wafers. These days, there are lot of devices using the wafers, including memory devices, sensors, solar cells, power devices and photonic devices. While the industry looks already matured, Internet of Things (IoT) is expected to be a new market of existing silicon-related products.
For process data of Si Deep Reactive Ion Etching (DRIE), please visit our Si DRIE page.
Si Nanoscale Etching
Nanoscale processing is required to achieve high performance and miniaturization of devices.
SAMCO’s Si nanoscale etching processes are used for various applications including photonic devices and nanoimprint.
Periodic arrays of vertical holes on SOI substrate
(hole diameter < 300 nm)
Photo courtesy of Baba lab,
Yokohama National University
Nanoimprint mold
Courtesy of RIKEN Nano Science Research Program
Nanopillar patterning (~20 nm width) for double-gate MOS fabrication
Photo courtesy of AIST
Si Etching for Photonic Devices
IoT will enable real-time data collection using industrial sensors and consumer products, and data centers need to be more efficient to process the collected “Big Data”. Silicon photonics are key technologies for high-speed data transfer and low power consumption at the data centers, replacing conventional copper interconnects.
SAMCO has developed silicon photonic device fabrication processes in collaboration with customers.
THz photonic crystal waveguide
Photo courtesy of University of Delaware
Si air-bridge photonic crystal
Photo courtesy of Baba lab,
Yokohama National University
Optical waveguide
Profile Angle Control
SAMCO has developed an technique to control the etched profile of silicon samples.
The angle is easily controllable from 57° to 86°.
57°
70°
86°
Si Isotropic Etching
Si isotropic etching was performed to fabricate emitter chip attays of Field Emission Display (FED).
The aspect ratio of array profiles is controllable with recipe adjustment.
XeF2 Release Etching for MEMS devices
Release etching is one of the important processes in MEMS device fabrication. The process is used for the release of various types of structures including cantilevers and comb arrays.
SAMCO offers reliable release etching solutions using Xenon Difluoride (XeF2 ).
The etch process is completely dry, and it eliminates the stiction problems that occur during wet etch process.
This isotropic etch process shows high etch selectivity of silicon against PDMS, parylene, SU8, silicon dioxide (SiO2) and silicon nitride (SiNx).
MEMS spiral structure after Si sacrificial layer etching
1 μm gap was formed using Si sacrificial layer etching and , and movable parylene structure was released.
Photo courtesy of Aoyagi lab at Kansai University
System Lineup for Si Dry Etching
RIE Systems
– Multiple system lineup for small wafers and 300/450 mm
– HIgh etch uniformity over the wafers
– Useful for etch tests of various materials
ICP Etch Systems
– Multiple system lineup for small wafers and 300/450 mm
– Superior profile control for Si photonic crystal fabrication
XeF2 Etch System
– Small footprint (tabletop-type)
– Excellent Si etch rate control for reliable MEMS release
– No stiction damages
Testimonial
SAMCO’s Si nanoscale etching technologies are used for photonic device fabrication at
University of Delaware
SAMCO’s XeF2 release etching technologies are used for MEMS device fabrication at
