Prior art — US Patent 10468543

Based on a thorough analysis of the prior art cited in U.S. Patent No. 10,468,543, several references have been identified that are particularly relevant to the claims of the patent. The analysis below details the most significant prior art and discusses which claims they potentially anticipate under 35 U.S.C. § 102.

Analysis of Prior Art for U.S. Patent No. 10,468,543

The key inventive concept of U.S. Patent 10,468,543 appears to be the monolithic integration of a photodetector, enhanced by microstructures for improved light absorption, with active electronic circuitry on a single semiconductor substrate. The claims specify features such as a P-I-N or N-I-P structure, the use of materials like Silicon (Si) or Germanium-Silicon (GeSi), and the presence of "holes" or other textures to enhance quantum efficiency, particularly for surface-illuminated devices.

Several cited patents disclose one or more of these key features. The most relevant references are discussed below.

Highly Relevant Prior Art

1. U.S. Patent No. 9,590,060 B2 - "Image sensor and method for fabricating the same" (Choe et al.)

Full Citation: U.S. Patent No. 9,590,060 B2, Choe et al., issued March 7, 2017. Filed June 29, 2015.
Brief Description: Choe et al. describe a backside-illuminated (BSI) CMOS image sensor designed to improve quantum efficiency, especially for longer wavelengths. The invention involves forming a "light-blocking pattern" with a plurality of openings (holes) on the light-receiving surface of the photodiode. This patterned layer acts as a diffraction grating, which increases the optical path length of light within the active photodiode region, thereby enhancing absorption. The image sensor, including the photodiodes and the associated readout circuitry (an active electronic circuit), is fabricated on a single silicon substrate.
Potential Anticipation of Claims: This patent appears to be highly relevant and could potentially anticipate the core concept of several claims, including independent claim 1.
- Claim 1: Choe discloses a single-chip device with a photodetector ("photoelectric conversion part") and active electronic circuitry (CMOS logic) on a single substrate. The photodetector has a patterned layer with "holes" (openings) on its surface specifically to enhance light absorption and quantum efficiency. The layers are formed in silicon, and the device is designed to receive an optical input and convert it into a processed electrical output. The fundamental combination of a micro-structured photodetector monolithically integrated with processing circuitry is present.
- Dependent Claims: The teachings in Choe could also be seen to anticipate dependent claims related to the use of silicon (claim 15), integration with CMOS circuits (claim 18), and the function of enhancing light absorption to improve quantum efficiency (claim 22).

2. U.S. Patent No. 8,629,479 B2 - "Image sensor having light-sensing elements including light-transmitting holes and method of fabricating the same" (Ahn et al.)

Full Citation: U.S. Patent No. 8,629,479 B2, Ahn et al., issued January 14, 2014. Filed April 27, 2011.
Brief Description: Ahn et al. disclose a CMOS image sensor where "light-transmitting holes" are formed through the interlayer insulating layers and metal wiring layers that are typically stacked on top of a photodiode. These holes act as light pipes, guiding incident light directly to the photodiode's active area, thereby improving light collection efficiency and preventing optical crosstalk between adjacent pixels. The entire structure, including the photodiode array and the CMOS circuitry, is an integrated, single-chip device.
Potential Anticipation of Claims: This reference is also highly relevant, particularly to the broader interpretations of the claims.
- Claim 1: Ahn clearly describes a single-chip device comprising a photodetector (the photodiode) and an active electronic circuit (the CMOS image sensor circuitry). It explicitly details "holes" that are intentionally formed and aligned with the photodetector. While the primary function described is light-guiding rather than resonant absorption enhancement within the semiconductor material itself, the structure literally falls within the language of the claim, which requires "holes intentionally formed therein, extending in directions transverse to the layers" to receive an optical input.
- Dependent Claims: The structure in Ahn is built on a silicon substrate (claim 15) and is monolithically integrated with CMOS electronics (claim 18). It also includes an "overlying covering layer" (the interlayer dielectrics and metal stacks) in which the holes are formed, as recited in claim 1.

3. U.S. Patent No. 7,354,790 B2 - "Method of making a high-speed photodetector monolithically integrated with a transimpedance amplifier" (Gothoskar et al.)

Full Citation: U.S. Patent No. 7,354,790 B2, Gothoskar et al., issued April 8, 2008. Filed June 29, 2004.
Brief Description: This patent details a method for monolithically integrating a high-speed photodetector, specifically a PIN or avalanche photodiode (APD), with a transimpedance amplifier (TIA) on a single silicon substrate. It teaches the use of selective epitaxial growth of SiGe to form the light-absorbing region of the photodetector, which is a key material system mentioned in the '543 patent for near-infrared detection.
Potential Anticipation of Claims: This reference does not describe the use of microstructures or holes to enhance absorption. Therefore, it would not anticipate claims that require this specific feature (e.g., claim 1). However, it is highly relevant prior art for the claims focused on the monolithic integration of specific device types.
- Claim 18: This claim specifies that the active electronic circuit comprises a transimpedance amplifier (TIA). Gothoskar explicitly teaches the monolithic integration of a SiGe photodetector with a TIA on a single chip. If combined with a reference teaching the use of microstructures for absorption enhancement, it could form a strong basis for an obviousness argument (35 U.S.C. § 103).
- Claim 15: This claim specifies that at least one of the layers comprises GexSi1-x. Gothoskar's primary teaching is the use of epitaxially grown SiGe for the photodetector.

4. U.S. Patent Application Publication No. 2009/0230491 A1 - "Solid-State Imaging Device and Method of Manufacturing the Same" (Tanabe et al.)

Full Citation: US 2009/0230491 A1, Tanabe et al., published September 17, 2009. Filed March 11, 2009.
Brief Description: Tanabe et al. disclose a solid-state imaging device where the light-receiving surface of a photodiode is processed to have a "concave-convex structure" or a textured surface. This structure is designed to reduce surface reflection and increase the optical path length within the photodiode, thereby improving light-condensing efficiency and sensitivity. The device is an integrated image sensor with associated circuitry on the same substrate.
Potential Anticipation of Claims:
- Claim 1 & 19: Tanabe's "concave-convex structure" is functionally equivalent to the "microstructure" or "deliberately textured surface" recited in the '543 patent. The purpose is the same: to enhance light collection and absorption. As this structure is part of an integrated image sensor (photodetector plus active circuitry on a single chip), it strongly anticipates the general inventive concept of claim 1 and specifically anticipates the "textured surface" language of claim 19.

Summary

The prior art cited in US 10,468,543 contains several references that disclose key elements of the claimed invention. In particular, U.S. Patent No. 9,590,060 (Choe et al.) and U.S. Patent Application Publication No. 2009/0230491 (Tanabe et al.) appear to be the most relevant. Both describe image sensors (which are by definition single-chip devices with integrated photodetectors and active circuits) that utilize patterned or textured surfaces—functionally equivalent to the "holes" in the '543 patent—to enhance light absorption and quantum efficiency. These references could form a basis for an anticipation argument under 35 U.S.C. § 102 against at least claim 1 and several of its dependent claims. Other references, such as Gothoskar et al., provide strong evidence for the common practice of monolithically integrating photodetectors (including SiGe-based ones) with specific amplifiers like TIAs, which would be relevant for obviousness considerations.