Project Title:

Low-cost, Low-noise, Filterless Solar-blind UV Detectors on SOI for Hydrogen Fire Monitoring

94-1	13.01	6000		

Low-cost, Low-noise, Filterless Solar-blind UV Detectors on SOI for 
Hydrogen Fire Monitoring 

Abstract:

Spire proposes to demonstrate low-cost, low-noise, highly-
efficient, compact imaging and detection systems for hydrogen-
fires. The proposed technology uses ultra-thin silicon-on-insulator 
(SOI) structures for fabricating filterless Si-based solar-blind 
detectors or imagers which can selectively and efficiently identify 
the ultraviolet signal from a hydrogen flame while having minimum 
sensitivity to visible and infrared background. By fabricating 
detectors on silicon thin films, the active device layer thickness 
can be chosen so that 310 nm UV light from hydrogen flames is 
absorbed within the device while longer wavelengths (> 400 nm) are 
absorbed in a substrate which is electrically isolated by a buried 
insulator. Therefore, the signal generated in the substrate (noise) 
is not detected in the active region on top. As a result, unlike 
conventional detection systems, SOI UV detectors will not require 
costly external filters to block out extraneous light. Furthermore, 
because of their compatibility with advanced Si processing 
technology, these solar-blind UV detectors and their associated 
readout electronics can both be fabricated on a single substrate at 
a fraction of the cost and physical size of existing alternatives. 
In Phase I, Spire will fabricate, test, and deliver to NASA 
individual hydrogen detectors configured as PN junction photodiodes 
on ultrathin SIMOX SOI structures. Phase II will optimize the 
design and process parameters for these devices and investigate a 
two-dimensional sensor array for imaging hydrogen flames. 

SIMOX solar-blind UV detectors and imagers have great potential for 
flame-out monitoring in aircraft engines and as hydrocarbon flame 
monitors (gas, oil, or coal) in residential and commercial heating 
systems and furnaces. These devices may also be used for monitoring 
ozone layer thickness. In addition, they have applications for 
analytical and clinical instruments.

Key Words

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