Method of forming high lateral voltage isolation structure involving two separate trench fills

摘要

In a SOI process, a high lateral voltage isolation structure is formed by providing at least two concentric dielectric filled trenches, removing the semiconductor material between the dielectric filled trenches and filling the resultant gap with dielectric material to define a single wide dielectric filled trench.

主权项

1. A method of isolating an active region in an SOI semiconductor chip that includes an insulating layer below the active region, against high lateral voltages, comprising
forming at least two initial trenches around the active region, the trenches extending substantially down to the insulating layer, depositing a dielectric in the trenches to define dielectric-filled trenches extending substantially down to the insulating layer, thereafter removing any semiconductor material between the dielectric-filled trenches to define at least one additional trench extending substantially down to the insulating layer, and depositing a dielectric in said at least one additional trench.