| 摘要 |
PROBLEM TO BE SOLVED: To improve the long term reliability of a transistor by carrying out ion implantation of fluorine after the formation of a source-drain region and then carrying out a heat treatment to suppress the slow trap. SOLUTION: First, gate electrodes 20, 21 are formed on a silicon substrate via a gate insulating film. Then, one conductivity type impurity is introduced into the gate electrodes and into the surface of the silicon substrate. Continuously, a first heat treatment is carried out. Then, after a silicon nitride film is formed as desired, fluorine is introduced into at least the gate electrodes 20, 21, and then a second heat treatment is carried out. If the second heat treatment is carried out in a predetermined temperature range after the introduction of fluorine, the SI-H bond and dangling bond of the silicon constituting a channel region 26, etc., are effectively substituted by the introduced fluorine to form Si-H bond so that the slow trap and hot channel effect can be suppressed more effectively. Further, the fluorine 24 having no contribution to the bond can be reduced and the deterioration of element characteristics can be prevented.
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