Prior art

To identify the most relevant prior art for US patent 7007259, I will examine the patent citations listed within the patent itself.

Here are the patent citations for US7007259B2 and their potential relevance:

1. US6093214A

• Full Citation: US6093214A, "Standard cell integrated circuit layout definition having functionally uncommitted base cells"
• Publication/Filing Date: Publication Date: July 25, 2000; Priority Date: February 26, 1998
• Brief Description: This patent generally relates to integrated circuit layout definition using standard cells with functionally uncommitted base cells. While it addresses aspects of integrated circuit layout, its primary focus is on standard cell methodology rather than dummy metal filling and its impact on clock nets.
• Potential Anticipated Claim(s) under 35 U.S.C. § 102: It is unlikely to anticipate the core claims of US7007259B2 (Claims 1, 18, 35) directly, as US7007259B2 specifically deals with "clock-net aware dummy metal using dummy regions" and prioritization based on clock nets, especially their widths and criticality. US6093214A does not appear to disclose the prioritization of dummy regions based on proximity or characteristics of clock nets.

2. US6446248B1

• Full Citation: US6446248B1, "Spare cells placement methodology"
• Publication/Filing Date: Publication Date: September 3, 2002; Priority Date: January 28, 2000
• Brief Description: This patent describes a methodology for placing spare cells in an integrated circuit. It concerns the placement of functional units, not the insertion of non-functional dummy metal for manufacturing planarity.
• Potential Anticipated Claim(s) under 35 U.S.C. § 102: Similar to US6093214A, this patent is unlikely to anticipate the specific dummy metal filling and clock-net aware prioritization aspects of US7007259B2's claims (Claims 1, 18, 35).

3. US6815811B2

• Full Citation: US6815811B2, "Semiconductor integrated circuit with dummy patterns"
• Publication/Filing Date: Publication Date: November 9, 2004; Priority Date: November 30, 2000
• Brief Description: This patent broadly discusses semiconductor integrated circuits with dummy patterns. It acknowledges the need for dummy patterns in manufacturing but does not explicitly detail the clock-net aware prioritization method of US7007259B2. While it addresses dummy patterns, its description of the placement method would need to specifically include the prioritization based on clock net adjacency, width, and criticality to directly anticipate the claims of US7007259B2.
• Potential Anticipated Claim(s) under 35 U.S.C. § 102: This patent could be a general reference for the concept of dummy patterns. However, without explicit disclosure of prioritizing dummy regions based on their adjacency to clock nets (and further based on clock net width/criticality) for the purpose of minimizing timing impact, it is unlikely to fully anticipate the specific method claims (Claims 1, 18, 35) of US7007259B2. It might address the broader concept of inserting dummy metal but not the specific "clock-net aware" aspect with prioritization.

4. US6751785B1

• Full Citation: US6751785B1, "System and method for limiting increase in capacitance due to dummy metal fills utilized for improving planar profile uniformity"
• Publication/Filing Date: Publication Date: June 15, 2004; Priority Date: March 12, 2002
• Brief Description: This patent addresses the issue of increased capacitance caused by dummy metal fills and aims to limit this increase to improve planar profile uniformity. This is highly relevant as it deals directly with the negative impact of dummy metal on circuit performance, which is a core problem US7007259B2 seeks to mitigate. The abstract mentions a method for limiting capacitance increase but does not explicitly detail the prioritization scheme of US7007259B2 involving clock nets.
• Potential Anticipated Claim(s) under 35 U.S.C. § 102: This patent is highly relevant as it addresses the core problem of parasitic capacitance due to dummy metal fill. Depending on the full description of its "limiting increase in capacitance" method, it could potentially anticipate aspects of claims related to minimizing timing impact (e.g., the preamble of Claim 1 or 18) if its method inherently or explicitly includes a similar prioritization or consideration of signal nets, especially critical ones like clock nets. However, without a detailed disclosure of prioritizing dummy regions adjacent to clock nets last and further by width/criticality, it might not fully anticipate the specific steps of US7007259B2's claims.

5. US20030177464A1

• Full Citation: US20030177464A1, "Integrated circuit layout method and program thereof permitting wire delay adjustment"
• Publication/Filing Date: Publication Date: September 18, 2003; Priority Date: March 15, 2002
• Brief Description: This patent application describes an integrated circuit layout method and program that allows for wire delay adjustment. This relates to timing, a critical aspect also addressed by US7007259B2. While it focuses on adjusting wire delay, it does not explicitly mention dummy metal filling or its clock-net aware prioritization.
• Potential Anticipated Claim(s) under 35 U.S.C. § 102: This document is relevant to timing optimization in integrated circuits. If its wire delay adjustment method implicitly or explicitly considers the placement of non-functional metal and prioritizes certain nets (like clock nets) in a way that aligns with US7007259B2, it could potentially anticipate certain claims. However, the abstract and general description do not immediately suggest the specific dummy fill prioritization scheme of US7007259B2.

6. US20030204832A1

• Full Citation: US20030204832A1, "Automatic generation method of dummy patterns"
• Publication/Filing Date: Publication Date: October 30, 2003; Priority Date: April 26, 2002
• Brief Description: This patent application describes an automatic generation method of dummy patterns. This is highly relevant as it directly concerns the process of creating dummy patterns. To anticipate US7007259B2, it would need to disclose the specific prioritization of dummy regions adjacent to clock nets, considering their width and criticality.
• Potential Anticipated Claim(s) under 35 U.S.C. § 102: This is a strong candidate for prior art as it describes an "automatic generation method of dummy patterns." If its detailed method for generating dummy patterns includes the steps of identifying dummy regions, determining adjacency to clock nets, assigning timing factors based on clock net characteristics (width, criticality), and prioritizing insertion accordingly to minimize timing impact (as in Claims 1, 18, and 35), then it could potentially anticipate these claims.

7. US20030229479A1

• Full Citation: US20030229479A1, "Dummy fill for integrated circuits"
• Publication/Filing Date: Publication Date: December 11, 2003; Priority Date: June 7, 2002
• Brief Description: This patent application pertains to "dummy fill for integrated circuits." This is another highly relevant piece of prior art. To anticipate US7007259B2, it would need to detail a method that specifically prioritizes dummy metal insertion based on clock net adjacency, width, and criticality to minimize timing impact.
• Potential Anticipated Claim(s) under 35 U.S.C. § 102: Similar to US20030204832A1, this document explicitly addresses "dummy fill for integrated circuits." If its method for dummy filling encompasses the specific prioritization steps related to clock nets as claimed in US7007259B2 (Claims 1, 18, 35), it would be a strong anticipatory reference.

Most Relevant Prior Art Summary:

Based on the titles and brief descriptions, US6751785B1, US20030204832A1, and US20030229479A1 appear to be the most relevant prior art. They directly address dummy metal filling and/or its impact on circuit performance. To determine actual anticipation, a full review of their specifications would be necessary to see if they disclose all the elements of US7007259B2's independent claims, particularly the specific clock-net aware prioritization scheme.

Specifically, US20030204832A1 ("Automatic generation method of dummy patterns") and US20030229479A1 ("Dummy fill for integrated circuits") are highly relevant because they directly concern the generation and insertion of dummy patterns, which is the core subject of US7007259B2. US6751785B1 ("System and method for limiting increase in capacitance due to dummy metal fills utilized for improving planar profile uniformity") is also very relevant as it aims to mitigate the negative electrical effects of dummy metal, which is a key objective of US7007259B2. The novelty of US7007259B2 largely resides in its specific prioritization strategy for dummy metal placement, especially concerning clock nets and their characteristics (width, criticality). Therefore, any prior art that discloses a similar clock-net aware prioritization method for dummy metal insertion would be highly anticipatory.