Ebara Corp v. Semigroup Texas LLC

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Ebara Corporation (Japan)
  • Defendant: Semigroup Texas, LLC (Texas); Warde Technology Materials, LLC (Texas); Warde Tec (Taiwan) Co., Ltd. (Taiwan)
  • Plaintiff's Counsel: Baker & Hostetler LLP
• Case Identification: 3:26-cv-02585, N.D. Tex., 08/04/2026
• Venue Allegations: Venue is alleged to be proper for the Texas-based defendants as they reside in the district and for the Taiwan-based defendant as it is a foreign corporation that may be sued in any judicial district.
• Core Dispute: Plaintiff alleges that Defendants' chemical mechanical polishing components, marketed as replacements for Plaintiff's products, infringe one utility patent and five design patents related to elastic membranes and substrate retaining rings.
• Technical Context: The technology relates to components for Chemical Mechanical Polishing (CMP), a critical process used in semiconductor manufacturing to achieve wafer surface planarization, which is essential for fabricating complex multi-layer integrated circuits.
• Key Procedural History: The complaint alleges that Defendants received a cease-and-desist letter identifying the asserted patents and accused activities on July 10, 2026, which may be relevant to the allegations of willful infringement.

Case Timeline

Date	Event
2013-05-15	Priority Date for D'849, D'200, D'990, D'349, D'180 Patents
2014-03-27	Priority Date for '244 Patent
2016-09-20	Issue Date for U.S. Patent No. D766,849
2016-10-18	Issue Date for U.S. Patent No. D769,200
2016-11-08	Issue Date for U.S. Patent No. D770,990
2017-02-21	Issue Date for U.S. Patent No. 9,573,244
2018-01-23	Issue Date for U.S. Patent No. D808,349
2018-03-20	Issue Date for U.S. Patent No. D813,180
2019-03-31	Warde Taiwan listed as organizer of Warde Texas
2025-05-23	Date noted on label of accused W6551 Test Head
2026-07-10	Date of alleged cease-and-desist correspondence
2026-08-04	Complaint Filing Date

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 9,573,244 - "Elastic Membrane, Substrate Holding Apparatus, and Polishing Apparatus"

• Patent Identification: U.S. Patent No. 9,573,244, "Elastic Membrane, Substrate Holding Apparatus, and Polishing Apparatus," issued February 21, 2017.

The Invention Explained

• Problem Addressed: The patent addresses the need to precisely control the polishing profile of a semiconductor wafer, particularly in a narrow area at the wafer's edge, which conventional elastic membranes struggled to achieve effectively for different polishing processes '244 Patent, col. 2:6-38
• The Patented Solution: The invention is an elastic membrane for a CMP apparatus featuring a specific structure of circumferential walls. It includes a first (outer) edge wall and a second (inner) edge wall connected by a horizontal portion. The geometry of this connection, with surfaces that are "perpendicular to the contact portion," creates two distinct, stacked pressure chambers (a first and second edge pressure chamber) that allow differential pressure to exert a highly localized downward force on the wafer edge '244 Patent, abstract '244 Patent, col. 9:25-49 '244 Patent, Fig. 4
• Technical Importance: This design provides more granular control over polishing pressure at the wafer periphery, enabling improved surface uniformity, which is critical for enhancing product yield in advanced semiconductor fabrication '244 Patent, col. 2:23-28

Key Claims at a Glance

• The complaint asserts independent claim 1 Compl. ¶42
• The essential elements of independent claim 1 include:
  • An elastic membrane with a contact portion for pressing a substrate.
  • A first edge circumferential wall extending upwardly from the contact portion's edge.
  • A second edge circumferential wall with a horizontal portion connected to the first wall's inner surface.
  • The inner surface of the first wall has upper and lower surfaces, both "perpendicular to the contact portion."
  • These surfaces, along with the horizontal portion of the second wall, define a "first edge pressure chamber" and a "second edge pressure chamber" located below the first.
  • The upper inner surface extends upwardly from the horizontal portion, and the lower inner surface extends downwardly from it.

U.S. Patent No. D766,849 - "Substrate Retaining Ring"

• Patent Identification: U.S. Patent No. D766,849, "Substrate Retaining Ring," issued September 20, 2016.

The Invention Explained

• Problem Addressed: Not applicable for a design patent.
• The Patented Solution: The patent protects the ornamental design for a substrate retaining ring, a component used in CMP equipment. The design's appearance is characterized by a circular ring with a specific pattern of evenly spaced circumferential notches or grooves on its bottom surface and particular proportional relationships between the grooved band and the ring's inner opening D'849 Patent, Figs. 1-10 Compl. ¶52
• Technical Importance: Substrate retaining rings are consumable components in CMP systems, and their specific design can be a recognizable feature of a manufacturer's product line.

Key Claims at a Glance

• The patent contains a single claim for "The ornamental design for a substrate retaining ring, as shown and described" D'849 Patent, claim The complaint alleges infringement of this claim Compl. ¶51

U.S. Patent No. D769,200 - "Elastic Membrane for Semiconductor Wafer Polishing Apparatus"

• Patent Identification: U.S. Patent No. D769,200, "Elastic Membrane for Semiconductor Wafer Polishing Apparatus," issued October 18, 2016 Compl. ¶24
• Technology Synopsis: The patent claims the ornamental design for an elastic membrane used in CMP. The design features a specific arrangement of concentric annular regions, circular bands, and progressive stepped or terraced radial transitions on its top surface Compl. ¶¶60-61
• Asserted Claims: The single design claim Compl. ¶59
• Accused Features: The elastic membrane installed in the accused W6551 Test Head and the membrane product SGC-4000-034-8500 are alleged to embody a design substantially the same as that claimed in the D'200 Patent Compl. ¶¶61-62 The complaint provides a visual overlay comparing a patent figure to a photograph of the accused W6551 Test Head Compl. p. 18, ¶61

U.S. Patent No. D770,990 - "Elastic Membrane for Semiconductor Wafer Polishing Apparatus"

• Patent Identification: U.S. Patent No. D770,990, "Elastic Membrane for Semiconductor Wafer Polishing Apparatus," issued November 8, 2016 Compl. ¶25
• Technology Synopsis: The patent claims the ornamental design for an elastic membrane. The claimed design is defined by its concentric annular structure, the relative spacing and widths of its circular bands, and its stepped or terraced transitions Compl. ¶¶68-69
• Asserted Claims: The single design claim Compl. ¶67
• Accused Features: The elastic membrane within the W6551 Test Head is alleged to have an overall visual impression that is the same as or substantially the same as the patented design Compl. ¶69

U.S. Patent No. D808,349 - "Elastic Membrane for Semiconductor Wafer Polishing Apparatus"

• Patent Identification: U.S. Patent No. D808,349, "Elastic Membrane for Semiconductor Wafer Polishing Apparatus," issued January 23, 2018 Compl. ¶26
• Technology Synopsis: The patent claims the ornamental design for an elastic membrane characterized by its concentric ring pattern, the relative widths and spacings of annular bands, and stepped or terraced transitions Compl. ¶77
• Asserted Claims: The single design claim Compl. ¶75
• Accused Features: The elastic membrane installed in the W6551 Test Head is alleged to display concentric annuli and stepped surfaces that align closely with the patented design Compl. ¶77

U.S. Patent No. D813,180 - "Elastic Membrane for Semiconductor Wafer Polishing Apparatus"

• Patent Identification: U.S. Patent No. D813,180, "Elastic Membrane for Semiconductor Wafer Polishing Apparatus," issued March 20, 2018 Compl. ¶27
• Technology Synopsis: The patent claims the ornamental design for an elastic membrane featuring concentric structures, stepped and terraced radial regions, and specific proportional relationships Compl. ¶85
• Asserted Claims: The single design claim Compl. ¶83
• Accused Features: The elastic membrane of the W6551 Test Head is alleged to exhibit a concentric ring system and stepped transitions that align closely with the ornamental geometry of the D'180 Patent Compl. ¶85

III. The Accused Instrumentality

Product Identification

The accused instrumentalities include the "W6551 Test Head" and other CMP components, such as elastic membranes and retaining rings, manufactured and/or supplied by Defendants Compl. ¶¶29-30 Specific accused products include Semigroup part numbers SGC-4000-032-4700, SGC-4000-034-8500, SGA-1122-767-0001, and SGC-3812-388-0001 Compl. ¶35

Functionality and Market Context

The accused products are components used in CMP systems for semiconductor manufacturing Compl. ¶2 The complaint alleges these products are marketed and sold as "drop-in replacements" for Ebara's own industry-recognized components, identifying them by corresponding Ebara part numbers (Compl. ¶¶29; Compl. ¶37). This marketing approach suggests the products are intended to be functionally and physically interchangeable with Ebara's originals. The complaint includes a photograph of the wafer-contact side of the W6551 Test Head, showing its concentric ring geometry and groove patterns Compl. p. 7, ¶30 A separate photograph shows a container for the test head bearing a label stating, "New 300mm GX carrier built with parts from Warde ready to be qualed [sic]" Compl. p. 8, ¶33

IV. Analysis of Infringement Allegations

'244 Patent Infringement Allegations

Claim Element (from Independent Claim 1)	Alleged Infringing Functionality	Complaint Citation	Patent Citation
a contact portion to be brought into contact with a substrate for pressing the substrate against a polishing pad;	The W6551 Test Head includes a contact portion that is brought into contact with a substrate, such as a semiconductor wafer, for pressing the substrate against a polishing pad.	¶43	col. 11:3-5
a first edge circumferential wall extending upwardly from a peripheral edge of the contact portion;	The membrane includes a first edge circumferential wall that extends upwardly from the peripheral edge of the contact portion.	¶43	col. 11:6-8
a second edge circumferential wall having a horizontal portion connected to an inner circumferential surface of the first edge circumferential wall,	The membrane includes a second edge circumferential wall having a horizontal portion that is connected to an inner circumferential surface of the first edge circumferential wall.	¶43	col. 11:9-12
wherein the inner circumferential surface of the first edge circumferential wall includes an upper inner circumferential surface and a lower inner circumferential surface, both of which are perpendicular to the contact portion,	The inner circumferential surface of the first edge circumferential wall comprises both an upper inner circumferential surface and a lower inner circumferential surface, each of which is perpendicular to the contact portion.	¶43	col. 11:13-17
the upper inner circumferential surface and an upper surface of the horizontal portion defining a first edge pressure chamber, and the lower inner circumferential surface and a lower surface of the horizontal portion defining a second edge pressure chamber located below the first edge pressure chamber,	The upper inner circumferential surface and the upper surface of the horizontal portion together define a first edge pressure chamber, while the lower inner circumferential surface and the lower surface of the horizontal portion together define a second edge pressure chamber located below the first edge pressure chamber.	¶43	col. 11:17-23
the upper inner circumferential surface extends upwardly from the horizontal portion of the second edge circumferential wall, and the lower inner circumferential surface extends downwardly from the horizontal portion of the second edge peripheral wall.	The upper inner circumferential surface extends upwardly from the horizontal portion of the second edge circumferential wall, and the lower inner circumferential surface extends downwardly from the horizontal portion of the second edge circumferential wall.	¶43	col. 11:24-29

D'849 Patent Infringement Allegations

The complaint alleges that the accused W6551 Test Head and the retaining ring marketed under part number SGA-1122-767-0001 infringe the D'849 Patent because they embody a design that is the same as or substantially the same as the patented design to an ordinary observer (Compl. ¶¶51; Compl. ¶53; Compl. ¶54). To support this, the complaint provides a side-by-side visual comparison, overlaying a bottom-plan view from the D'849 Patent onto a photograph of the accused W6551 Test Head's retaining ring Compl. p. 16, ¶53 This visual alleges that the ring's circumference, evenly spaced notches, and the proportions of the grooved band closely align with the patented design Compl. ¶53

Identified Points of Contention

• Technical Question ('244 Patent): The infringement allegation for the '244 patent hinges on the accused product having a very specific geometry. This raises the question of what evidence the complaint provides that the accused membrane's inner circumferential surfaces are truly "perpendicular to the contact portion," as required by the claim, rather than simply angled in a way that achieves a similar function. The complaint makes a conclusory allegation on this point, which will likely be a central focus of expert discovery and analysis Compl. ¶43
• Scope Question (Design Patents): For the design patents, the dispute may center on the "ordinary observer" standard in the context of a specialized industrial market. The complaint argues that even without images, purchasers in the industry would recognize the infringing nature of the "drop-in replacements" due to their familiarity with Ebara's original components Compl. ¶54 This raises the question of whether the "ordinary observer" is a layperson or a person with specialized knowledge of CMP components, and how that impacts the comparison of the overall visual impression.

V. Key Claim Terms for Construction

• The Term: "perpendicular to the contact portion" '244 Patent, claim 1
• Context and Importance: This term defines a critical geometric relationship that, according to the patent, enables the creation of two distinct edge pressure chambers for precise, localized force application. The infringement analysis for the '244 patent will turn on whether the accused product's structure meets this precise geometric constraint. Practitioners may focus on this term because the patent's own specification contrasts this "perpendicular" arrangement with less effective "inclined" arrangements, suggesting the term is a key point of novelty '244 Patent, Figs. 5-9
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: A party arguing for a broader scope might suggest that for a component described as an "elastic membrane," the term "perpendicular" should be understood to accommodate minor variations from a perfect 90-degree angle that are inherent in the manufacturing and flexing of a rubber-like material. The patent does not explicitly provide language supporting this, but the physical nature of the invention could be used to argue against a mathematically rigid interpretation.
  • Evidence for a Narrower Interpretation: The patent specification provides strong support for a narrow, literal interpretation. The claim language is precise. The summary of the invention recites the perpendicularity of both the upper and lower inner circumferential surfaces '244 Patent, col. 2:57-60 The detailed description explicitly states that this configuration prevents an oblique force from being applied, which distinguishes it from prior art '244 Patent, col. 10:15-25 Figure 9 is specifically presented to show the claimed perpendicular configuration, in contrast to the inclined configurations of Figures 5-8, reinforcing its importance '244 Patent, col. 4:18-29

VI. Other Allegations

• Indirect Infringement: The complaint alleges induced infringement of the '244 patent, stating that Defendants knowingly encourage infringement by providing the accused products with instructions and marketing them as "drop-in replacements" for Ebara's patented components Compl. ¶45 Contributory infringement is alleged on the basis that the accused products are especially made for use in an infringing manner and have no substantial non-infringing uses Compl. ¶46
• Willful Infringement: Willfulness is alleged for the '244 patent based on Defendants' continued infringement after receiving actual notice via a cease-and-desist letter on July 10, 2026 (Compl. ¶¶28; Compl. ¶47). The prayer for relief requests a finding of willfulness for all asserted patents based on this notice Compl. p. 28, ¶A

VII. Analyst's Conclusion: Key Questions for the Case

1. A core issue of claim construction and proof will be central to the utility patent claim: does the accused elastic membrane's wall structure meet the '244 patent's specific claim requirement of being "perpendicular to the contact portion," or will the analysis depend on a functional comparison under the doctrine of equivalents?
2. For the five asserted design patents, a key question will be the application of the ordinary observer test in a specialized market: given that the accused products are marketed as "drop-in replacements" to sophisticated industrial consumers, will a court find the overall visual impression of the accused components to be substantially the same as Ebara's patented designs, even if minor differences exist or if products are sold without detailed images?
3. The case will likely involve a significant dispute over damages and intent, particularly regarding the design patents. The allegation of selling "drop-in replacements" coupled with alleged notice of infringement raises the question of whether Plaintiff can prove the copying required for disgorgement of total profits under 35 U.S.C. § 289 and the deliberate conduct required for a finding of willfulness.