Silicon Photomultipliers (SiPMs) are novel, solid state based low level light detectors. KETEK is utilizing for its SiPM production an ultraclean silicon processing to avoid any contaminations causing an increase of the dark count rate. Important aspects of the well-established and for many years optimized KETEK Silicon Drift Detector technology were transferred to the SiPM process. KETEK SiPMs are processed on 200 mm wafers using a 0.35 µm stepper lithography, providing cost effective production. KETEK SiPMs are produced very cost-effective in silicon CMOS foundries with high throughput rates and almost no volume limitation. In the same way the packaging is done on wafer level. Therefore the volumes can be scaled to nearly any imaginable customer demand within shortest time.

Due to the distinguished properties of SiPMs, especially the very high quantum efficiency compared to the established PMTs and the much higher gain compared to APDs, they are able to replace PMTs and APDs in many applications. The table below compares the main features of PMT, APD and SiPM.

Comparison Chart

PMT vs. APD vs. SiPM

PMT Photomultiplier Tube APD Avalanche Photodiode SiPM Silicon Photomultiplier
Quantum Efficiency 25% to 40% up to 80% up to 80%
Single Photon Resolution
Operation Voltage 1 – 3 kV 100 – 500 V 20 – 40 V
Gain 104 – 109 30 – 300 105 – 107
Temperature Dependence Low High Low
No Damage in Bright Light
Homogeneous Response across Photosensitive Area
Insensitivity to Magnetic Field
Production Costs Medium Low Low

Working Principle

How SiPMs are working.

Device Parameters

Key parameters of SiPMs explained.

Microcell Construction

The structure of KETEK SiPMs.