Blank Wafer
 |
The fabrication process starts with a standard,
monocrystalline silicon wafer. |
KOH Etching
 |
A cavity is formed in the wafer using a wet
chemical etching process. This etch determines the separation
of the device's capacitive elements. |
Deep Boron Diffusion
 |
The base of the capacitive membrane is formed
using a deep boron diffusion process. |
Shallow Boron Diffusion
|
The sensor's actual membrane is formed with
a shallow boron diffusion process. It is this membrane that
will move in response to any changes in the external pressure. |
Anodic Bonding
|
The base of the sensor is attached to a glass
substrate using anodic bonding. |
Wafer Dissolution
|
The undoped silicon wafer is literally dissolved
away, (hence the process' name), leaving the freestanding microstructure. |
