Sensonor SW4 intro

SensoNor’sProsess SW4: 

SensoNor’s Prosess SW4 Henrik Jakobsen HVE

Slide2: 

BELP - 2 chip packaging technology PRESSURE SENSOR MICROSYSTEM

SensoNor Fab technologies: 

SensoNor Fab technologies Our strategy is to use “bulk-micromachining” of silicon as flexible high-yield standard processes The technology shall add unique features to microsystem products

Front-end technology ”menu”: 

Front-end technology ”menu”

Slide5: 

SW1 Technology N-type silicon P+ P++ P+ P++ 840 P+ P++ Sensor principle: piezoresistivity AE800 Processing on both sides of thin 2” wafers: symmetric with same process and pattern on both sides of wafer deep diffusions and low sheet resistivities

Slide6: 

SW2 Technology Sensor principle: piezoresistivity Process: Standard implanted resistors Anisotropic etch with time based stop AE880

Slide7: 

SW3 Technology Sensor principle: piezoresistivity Process: High-stability buried resistors Anisotropic etch with time-based stop Option: NiCr/Au back-side metallization SP82

Standard process platform SW4: 

Standard process platform SW4 Sensing principles: Piezoresistive Resonant structures (beams and plates) Actuation principle: Thermal Main technology: Silicon planar Electrochemical etch stop ICP-RIE Wafer lamination by anodic bonding Chemical micromachining of glass Features: Sealed cavities with electrical vias Two micro-machined thicknesses High stability piezoresistors for high accuracy Shallow piezoresistors Ultra flat surface

SW4 - the “Foundry” MPW-process: 

SW4 - the “Foundry” MPW-process Potential Applications: Pressure and flow sensors Accelerometers Micro actuators Micro fluidic components Precision structures for optical devices

SW4 highlights: 

SW4 highlights High-aspect-ratio etching with RIE Sealed cavity with electrical interconnect crossings High stability piezoresistors for sensing elements High-precision diaphragm definition by PN etch stop 3D-structuring of diaphragm is possible

Slide11: 

Microstructures Glass with recesses and via holes Silicon with recesses and via holes isotropic 90 deg walls 54.7 deg walls

Slide12: 

Absolute pressure sensors Vacuum cavity Pressure inlet port Diaphragm Glass Silicon Glass Wire bond pads

Slide13: 

Relative pressure sensors Pressure inlet port 2 Diaphragm Glass Silicon Glass Wire bond pads Pressure inlet port 1

Slide14: 

Differential sensor with bottom ports

Slide15: 

Unique 3-D structures Combining wet etching and dry etching to make 3D structures

Process 4 - cross-section : 

Process 4 - cross-section