Examples of photomasks design:
van der Pauw type structures - 
left,   test of HEMT heterostructures - 
middle,   contact structures - 
right:
 
 
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A matrix of resonant-tunnelling diodes (RTDs) and transistors (HEMTs) on the same 
heterostructures (square expanded contacts side length = 100 µm  ). 
 
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Structures for Hall effect measurements (width of the horizontal gate stripe = 400 µm ) - left,
 
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Semiconductor chip comprising a set of photo diodes - left, detail of the central diode - right
 
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RTD samples prepared on GaAs/GaAlAs heterostructures - left,
 
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Microstructures based on sputtered piezoresistive layers on silicon substrates:
 
 
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Wired structures in packages designed for their experimental study:
structures for Hall-effect measurements (ceramic chip-carrier package - CCC18) - left,
 
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Floating assembly of a deformation-microsensor silicon chip
 - right,
detail of the adjusted microsensor chip structure
 - left,  
(width of the chip  = 2.5 mm  ):
 
 
 
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Samples prepared for high-frequency measurements:
RTD assembled - top left, 
detail of the bonded RTD chip - right 
(expanded contacts side length  = 100 µm  ),
reference commercial HEMT assembly - 2nd row:
 
 
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