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:
Nov. 24, 2009
Filed:
Jun. 20, 2006
Mitsushi Fujiki, Kawasaki, JP;
Katsuyoshi Matsuura, Kawasaki, JP;
Genichi Komuro, Kawasaki, JP;
Fujitsu Microelectronics Limited, Tokyo, JP;
Abstract
A ferroelectric capacitor formation method necessary for stably fabricating an FeRAM and a semiconductor device fabrication method. After a PZT film is deposited on a lower electrode layer, the PZT film is crystallized by performing heat treatment in an atmosphere of a mixed gas which contains Ogas and Ar gas. In this case, the flow rate of the Ogas is controlled by one mass flow controller. The flow rate of the Ar gas used for purging and the flow rate of the Ar gas used for adjusting Ogas concentration are controlled by different mass flow controllers. Before raising the temperature, the Ogas, the Ar gas used for purging, and the Ar gas used for adjusting Ogas concentration are made to flow at predetermined flow rates. Only the Ar gas used for purging is stopped, raising the temperature is begun, and the heat treatment is performed. At this time the Ogas and the Ar gas used for adjusting Ogas concentration flow at the predetermined flow rates. As a result, an atmosphere in which the heat treatment is performed for crystallizing the PZT film can be stabilized. Accordingly, a ferroelectric capacitor having predetermined performance is stably formed and an FeRAM is stably fabricated.