Method and structure of monolithically integrated infrared sensing device

• US 8,120,076 B2
• Filed: 07/28/2009
• Issued: 02/21/2012
• Est. Priority Date: 07/28/2008
• Status: Expired due to Fees

• Current Assignee: Movella Incorporated (Movella Holdings, Inc.)
• Original Assignee: mCube, Inc.
• Inventors: Yang, Xiao (Charles)
• Primary Examiner(s): STARK, JARRETT J
• Application Number:
  US12/511,004
• Publication Number:
  US 20100187580A1
• Time in Patent Office: 938 Days
• Field of Search: 257/290, 257/291, 257/E27.131, 257/E31.11, 257/E31.093
• US Class Current: 257/291
• CPC Class Codes: H01L 27/14627 Microlenses
• CPC Class Codes: H01L 27/14669 Infrared imagers
• CPC Class Codes: H01L 27/14685 Process for coatings or optical elements
• CPC Class Codes: H01L 27/14692 Thin film technologies, e.g. amorphous, poly, micro- or nanocrystalline silicon

Abstract

Protection for infrared sensing device, and more particularly, to a monolithically integrated uncooled infrared sensing device using IC foundry compatible processes. The proposed infrared sensing device is fabricated on a completed IC substrate. In an embodiment, the infrared sensing device has a single crystal silicon plate with an absorbing layer supported a pair of springs. The absorbing layer absorbs infrared radiation and heats up the underlying silicon layer. As a result, an n well in the silicon layer changes its resistance related to its temperature coefficient of resistance (TCR). In another embodiment, the infrared sensing device has a top sensing plate supported by an underlying spring structures. The top sensing plate has sensing materials such as amorphous silicon, poly silicon, SiC, SiGe, Vanadium oxide, or YbaCuO. Finally, a micro lens array is placed on top of the sensing pixel array with a gap in between. In an embodiment, the micro lens array is fabricated on a silicon substrate and bonded to the sensing pixel array substrate. In another embodiment, the micro lens array is fabricated monolithically using amorphous silicon. The micro lens array layer encapsulates the pixel sensing array hermetically, preferably in a vacuum environment.

Claims

1. An integrated imager and CMOS integrated circuit device comprising:

a semiconductor substrate having a surface region;

a CMOS integrated circuit device region overlying the surface region;

a dielectric material overlying the CMOS integrated circuit device region;

one or more infrared (IR) sensing devices overlying the dielectric material, the IR sensing device(s) being coupled to the CMOS integrated circuit device region, the IR sensing device(s) each having a sensing plate supported by a pair of springs, wherein the sensing plate comprises a top layer and a bottom layer, the top layer comprising a CCD or CMOS imaging element that senses visible wavelengths; and

one or more micro lens devices coupled to the one or more IR sensing devices.

2. The device of claim 1 wherein the sensing plate comprises a material selected from amorphous silicon, polysilicon, silicon carbide, silicon, germanium, vanadium oxide, or YBaCuO.

3. The device of claim 1 wherein each pair of springs of each IR sensing device is coupled to the semiconductor substrate via a pair of anchors.

4. The device of claim 1 wherein the bottom layer comprises an infrared sensing material.

5. The device of claim 1 wherein the one or more IR sensing devices comprise an array of IR sensing pixels.

6. The device of claim 5 wherein the one or more lens devices comprise and array of micro lenses, the micro lens array encapsulating the IR sensing pixel array.

7. The device of claim 1 wherein the CMOS integrated circuit device region includes logic integrated circuits.