8-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C.  20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of The Securities Exchange Act of 1934

Date of Report (date of earliest event reported):

July 25, 2008

Cabot Microelectronics Corporation

(Exact name of registrant as specified in its charter)

Delaware	000-30205	36-4324765
(State or other jurisdiction of incorporation)	(Commission File Number)	(IRS Employer Identification)

870 Commons Drive, Aurora, Illinois	60504
(Address of principal executive offices)	(Zip Code)

(630) 375-6631

(Registrant’s telephone number, including area code)

Not applicable

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

o   Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

o   Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

o   Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

o   Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

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Item 8.01                      Other Events

On July 30, 2008, Cabot Microelectronics Corporation issued a press release entitled “Cabot Microelectronics Corporation Receives Ruling in Markman Hearing in Patent Infringement Enforcement Action Against DuPont Air Products NanoMaterials, LLC.”  A copy of the press release is attached hereto as Exhibit 99.1 and incorporated herein by reference.

This information is being furnished pursuant to Item 8.01 of Form 8-K and shall not be deemed “filed” for purposes of Section 18 of the Securities and Exchange Act of 1934, as amended (the “Exchange Act”), or incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

Item 9.01                      Financial Statements and Exhibits.

(c)	Exhibits The following exhibit is being furnished, not filed, herewith pursuant to Item 8.01 of Form 8-K:
	99.1           Press release, dated July 30, 2008, entitled “Cabot Microelectronics Corporation Receives Ruling in Markman Hearing in Patent Infringement Enforcement Action Against DuPont Air Products NanoMaterials, LLC.”

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SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

	CABOT MICROELECTRONICS CORPORATION
Date: July 30, 2008	By:	/s/ WILLIAM S. JOHNSON
		William S. Johnson
		Vice President and Chief Financial Officer
		[Principal Financial Officer]

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INDEX TO EXHIBITS

Exhibit Number	Title
99.1	Press release, dated July 30, 2008, entitled “Cabot Microelectronics Corporation Receives Ruling in Markman Hearing in Patent Infringement Enforcement Action Against DuPont Air Products NanoMaterials, LLC.”

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EX-99.1

CABOT MICROELECTRONICS CORPORATION RECEIVES

RULING IN MARKMAN HEARING IN PATENT INFRINGEMENT ENFORCEMENT ACTION AGAINST

DUPONT AIR PRODUCTS NANOMATERIALS, LLC

AURORA, IL, July 30, 2008 – Cabot Microelectronics Corporation (Nasdaq:  CCMP), the world’s leading supplier of chemical mechanical planarization (CMP) polishing slurries to the semiconductor industry, today announced that on July 25, 2008, the United States District Court for the District of Arizona issued its patent claim construction, or “Markman” Order (“Markman Order”) in Cabot Microelectronics’ ongoing patent infringement litigation against DuPont Air Products NanoMaterials, LLC (“DA Nano”).

In a Markman ruling, a district court hearing a patent infringement case interprets and rules on the scope and meaning of disputed patent claim language regarding the patents in suit.  A Markman decision is often a significant factor in the progress and outcome of patent infringement litigation.

In the recently issued Markman Order, the Court adopted interpretations that Cabot Microelectronics believes are favorable to Cabot Microelectronics on all claim terms that were in dispute in the litigation.

The litigation, which the company previously announced it had filed in January, 2007, involves DA Nano’s manufacture and marketing of certain CMP slurries that the company believes infringe five patents owned by Cabot Microelectronics.  The affected DA Nano products include certain products used for tungsten CMP.  Cabot Microelectronics is seeking damages and injunctive relief against DA Nano in the litigation.

“We are extremely pleased with the Court’s Markman Order.  We remain confident in our position concerning DA Nano’s infringement of the patents at issue, and look forward to proceeding to trial,” said H. Carol Bernstein, Cabot Microelectronics' Vice President, Secretary and General Counsel.  “While the outcome of this and any legal matter cannot be predicted with certainty, we believe the Court’s Markman Order is another significant step towards the successful resolution of this litigation, and further validates Cabot Microelectronics’ ongoing commitment to the enforcement of our intellectual property and protection of our significant investment in patent-protected research and development.”

The Court’s Markman Order and related Order are accessible by following the links below:

Markman Order (July 25, 2008)    http://media.corporate-ir.net/media_files/irol/12/120920/Markman_Order_072508.pdf

                Order Unsealing Markman Order (July 30, 2008)   http://media.corporate-ir.net/media_files/irol/12/120920/Order_Unsealing_Markman_Order_073008.pdf  


ABOUT CABOT MICROELECTRONICS CORPORATION

Cabot Microelectronics Corporation, headquartered in Aurora, Illinois, is the world's leading supplier of CMP slurries used in semiconductor and data storage manufacturing. The company's products play a critical role in the production of the most advanced semiconductor devices, enabling the manufacture of smaller, faster and more complex devices by its customers.  Since becoming an independent public company in 2000, the company has grown to approximately 800 employees on a global basis.  The company's vision is to become the world leader in shaping, enabling and enhancing the performance of surfaces, so the company is leveraging its expertise in CMP slurry formulation, materials and polishing techniques developed for the semiconductor industry and applying it to demanding surface modification applications in other industries where shaping, enabling and enhancing the performance of surfaces is critical to success. For more information about Cabot Microelectronics Corporation, visit www.cabotcmp.com or contact Amy Ford, Director of Investor Relations at (630) 499-2600.

SAFE HARBOR STATEMENT

This news release may include statements that constitute "forward looking statements" within the meaning of federal securities regulations.  These forward-looking statements include statements related to: future sales and operating results; company and industry growth or trends; growth of the markets in which the company participates; international events; product performance; the generation, protection and acquisition of intellectual property, and litigation and outcome of litigation related to such intellectual property; new product introductions; development of new products, technologies and markets; the acquisition of or investment in other entities; uses and investment of the company’s cash balance; and the construction of facilities by Cabot Microelectronics Corporation.  These forward-looking statements involve a number of risks, uncertainties, and other factors, including those described from time to time in Cabot Microelectronics' filings with the Securities and Exchange Commission (SEC), that could cause actual results to differ materially from those described by these forward-looking statements.  In particular, see "Risk Factors" in the company’s quarterly report on Form 10-Q for the quarter ended March 31, 2008 and in the company’s annual report on Form 10-K for the fiscal year ended September 30, 2007, both filed with the SEC.  Cabot Microelectronics assumes no obligation to update this forward-looking information.