Method and device for photodetector circuit with selectively transparent buffer

A method for manufacturing a sensor device, the method comprising:

• providing a silicon substrate comprising a backside region and a frontside region;
• forming a GaAs buffer region overlying the frontside region;
• forming a wavelength configuring material for a target wavelength range, the wavelength configuring material comprising a selectively transparent region, the selectively transparent region comprising a plurality of material regions in a stacked configuration having at least a first material composition and a second material composition, the first material composition comprising an InGaP material, an InP material, or a strained layer superlattice (SLS) material;
• and the second material composition comprising an InP spacer material;
• and wherein the plurality of material regions includes an interface region between each adjacent pair of the material regions;
• forming an n-type contact region overlying the wavelength configuring material, the n-type contact region comprising InP, InGaAs, InGaAsP, InAlGaAs, or InAlAs;
• forming a InGaAs absorber region overlying the n-type contact region;
• forming one or more InGaAsP or InAlGaAs band transition regions overlying the InGaAs absorber region;
• forming a p-type spacer region overlying the InGaAsP or InAlGaAs band transition regions;
• and
• forming a p-type contact region overlying the p-type spacer region.