CMOS image sensor
First Claim
1. A method of constructing process architecture to fabricate back-side illuminated image sensor matrices, the process architecture comprising fully-depleted CMOS devices, and photo-diodes incorporating epitaxially grown regions, the method comprising:
- (a) selecting a Thin-Film Silicon-On-Insulator (TF-SOI) or Thin-Film Germanium-On-Insulator (TF-GeOI or TF-GOI) substrate, comprising a top thin semiconductor film, a buried insulator comprising a back surface that faces a bottom thick semiconductor substrate;
(b) fabricating the fully-depleted CMOS devices and circuitry incorporating the fully-depleted CMOS devices on the top thin semiconductor film;
(c) Epitaxially growing photo-diode active layers on the top thin semiconductor film;
(d) fabricating dense metal interconnects over each of the image sensor matrices, including over the photo-diode regions, on a top of the thin semiconductor film;
(e) removing the bottom thick semiconductor substrate, after full processing of a front-side of the top thin semiconductor film;
(f) fabricating monolithically integrated structures on the back surface of the buried insulator, aligned to the dense metal interconnects made on the top thin semiconductor film;
(g) bonding to a new mechanical substrate that is transparent to wavelengths of interest, of the back surface of the buried insulator after fabricating the monolithically integrated structures; and
(h) dicing and packaging each of the fully-depleted CMOS devices, or wafer-level packaging followed by separation of individual CMOS image sensor matrix chips.
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Accused Products
Abstract
Light sensing devices are monolithically integrates with CMOS devices on Thin-Film Silicon-On-insulator (TF-SOI) or Thin-Film Germanium-On-Insulator (TF-GeOI) substrates. Photo-diode active layers are epitaxially grown on the front-side of the substrate and after full processing of the front-side of the substrate, the substrate material is removed under the buried insulator (buried oxide). Monolithically integrated structures are then fabricated on the back of the buried oxide. The back-side is then bonded to a new substrate that is transparent to the wavelengths of interest. For example, quartz, sapphire, glass, or plastic, are suitable for the visible range. Back-side illumination of the sensor matrix is thereby allowed, with light traveling through the structures fabricated on the back of the substrate, opposite to the side on which CMOS is made.
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Citations
20 Claims
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1. A method of constructing process architecture to fabricate back-side illuminated image sensor matrices, the process architecture comprising fully-depleted CMOS devices, and photo-diodes incorporating epitaxially grown regions, the method comprising:
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(a) selecting a Thin-Film Silicon-On-Insulator (TF-SOI) or Thin-Film Germanium-On-Insulator (TF-GeOI or TF-GOI) substrate, comprising a top thin semiconductor film, a buried insulator comprising a back surface that faces a bottom thick semiconductor substrate; (b) fabricating the fully-depleted CMOS devices and circuitry incorporating the fully-depleted CMOS devices on the top thin semiconductor film; (c) Epitaxially growing photo-diode active layers on the top thin semiconductor film; (d) fabricating dense metal interconnects over each of the image sensor matrices, including over the photo-diode regions, on a top of the thin semiconductor film; (e) removing the bottom thick semiconductor substrate, after full processing of a front-side of the top thin semiconductor film; (f) fabricating monolithically integrated structures on the back surface of the buried insulator, aligned to the dense metal interconnects made on the top thin semiconductor film; (g) bonding to a new mechanical substrate that is transparent to wavelengths of interest, of the back surface of the buried insulator after fabricating the monolithically integrated structures; and (h) dicing and packaging each of the fully-depleted CMOS devices, or wafer-level packaging followed by separation of individual CMOS image sensor matrix chips. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification