Semiconductor structures and methods for forming isolation between Fin structures of FinFET devices

摘要

Semiconductor structures and methods for forming isolation between fin structures formed from a bulk silicon wafer are provided. A bulk silicon wafer is provided having one or more fin structures formed therefrom. Forming of the fin structures defines isolation trenches between the one or more fin structures. Each of the fin structures has vertical sidewalls. An oxide layer is deposited in the isolation trenches and on the vertical sidewalls using HDPCVD in about a 4:1 ratio or greater. The oxide layer is isotropically etched to remove the oxide layer from the vertical sidewalls and a portion of the oxide layer from the bottom of the isolation trenches. A substantially uniformly thick isolating oxide layer is formed on the bottom of the isolation trench to isolate the one or more fin structures and substantially reduce fin height variability.

主权项

1. A method for forming a finFET device in a semiconductor substrate comprising the steps of:
forming fin structures from the semiconductor substrate, the fin structures including vertical sidewalls, the step of forming the fin structures defining isolation trenches on the exposed semiconductor substrate between the fin structures; depositing an oxide to form an oxide layer on horizontal exposed surfaces in the bottom of the isolation trenches and on vertical surfaces of the vertical sidewalls of the fin structures with the oxide layer in the bottom of the isolation trenches having a greater thickness than the oxide layer on the vertical sidewalls; and removing the oxide layer from the vertical sidewalls and at least a portion from the isolation trenches to form a uniformly thick isolating oxide layer in the isolation trenches.