| 摘要 |
A zirconium oxide gate dielectric is utilized to make a transistor for an integrated circuit. In forming the transistor which uses the zirconium oxide as the gate dielectric, the zirconium oxide is etched using phosphoric acid. This phosphoric acid is a wet etch performed at an elevated temperature to achieve a simultaneous etch of a silicon nitride anti-reflective coating which overlies the gate. This use of phosphoric acid is effective because the etch is stopped by silicon oxide so that the underlying silicon substrate is protected. Also, the field oxide is not etched in any appreciable amount. Thus, the field oxide thickness is unchanged as a result of the etch.
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