The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 15, 2013
Filed:
Oct. 21, 2011
IL Kwan Lee, San Ramon, CA (US);
Il Kwan Lee, San Ramon, CA (US);
Alpha & Omega Semiconductor Inc., Sunnyvale, CA (US);
Abstract
A method is disclosed for forming a patterned thick metallization atop a semiconductor chip wafer. The method includes fabricating a nearly complete semiconductor chip wafer ready for metallization; depositing a bottom metal layer of sub-thickness TKtogether with its built-in alignment mark using a hot metal process; depositing a top metal layer of sub-thickness TKusing a cold metal process thus forming a stacked thick metallization of total thickness TK=TKTK; then, use the built-in alignment mark as reference, patterning the stacked thick metallization. A patterned thick metallization is thus formed with the advantages of better metal step coverage owing to the superior step coverage nature of the hot metal process as compared to the cold metal process; and lower alignment error rate owing to the lower alignment signal noise nature of the cold metal process as compared to the hot metal process.