Very large scale heterogeneous integration (VLSHI) and wafer-level vacuum packaging for infrared bolometer focal plane arrays

• Imaging in the long wavelength infrared (LWIR) range from 8 to 14 μm is an extremely useful tool for non-contact measurement and imaging of temperature in many industrial, automotive and security applications. However, the cost of the infrared (IR) imaging components has to be significantly reduced to make IR imaging a viable technology for many cost-sensitive applications. This paper demonstrates new and improved fabrication and packaging technologies for next-generation IR imaging detectors based on uncooled IR bolometer focal plane arrays. The proposed technologies include very large scale heterogeneous integration for combining high-performance, SiGe quantum-well bolometers with electronic integrated read-out circuits and CMOS compatible wafer-level vacuum packing. The fabrication and characterization of bolometers with a pitch of 25 μm × 25 μm that are arranged on read-out-wafers in arrays with 320 × 240 pixels are presented. The bolometers contain a multi-layer quantum well SiGe thermistor with a temperature coefficient of resistance of -3.0%/K. The proposed CMOS compatible wafer-level vacuum packaging technology uses Cu-Sn solid-liquid interdiffusion (SLID) bonding. The presented technologies are suitable for implementation in cost-efficient fabless business models with the potential to bring about the cost reduction needed to enable low-cost IR imaging products for industrial, security and automotive applications.

Nyckelord

Bolometer

IR

MEMS

Thermal imaging

Very large scale heterogeneous integration

Automotive applications

Cost-sensitive applications

Fabrication and characterizations

Heterogeneous integration

Long-wavelength infrared ranges

Noncontact measurements

Temperature coefficient of resistance

Wafer level vacuum packaging

Bolometers

CMOS integrated circuits

Cost reduction

Infrared detectors

Infrared imaging

Infrared radiation

Integration

Iridium

Semiconductor quantum wells

Silicon alloys

Technology

Vacuum

Wafer bonding

Electronics packaging

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)