Process for digging a deep trench in a semiconductor body and semiconductor body so obtained
OwnerRoberto Colomboinventor
Life of this patent
Estimating the term…
Abstract
A process for digging deep trenches in a body of semiconductor material includes forming a mask having an opening, above a surface of a semiconductor body. A passivating layer is conformally formed on the mask and on the semiconductor body within the opening. A directional etch is extended to first remove the passivating layer from on top of the semiconductor body and then etch the semiconductor body through the opening. Forming the passivating layer and executing the directional etch are carried out repeatedly in sequence so as to form a trench through the opening. A tapered portion of the trench is formed, which has a transverse dimension decreasing as a distance from the surface of the semiconductor body increases.
Claims23
A process for digging a deep trench in a body of semiconductor material, comprising the steps of:
- on a surface of a semiconductor body, forming a mask having at least one opening;
- forming a passivating layer conformally on said mask and on said semiconductor body within said opening;
- executing a directional etch so as to first remove said passivating layer at least from above said semiconductor body and then etch said semiconductor body through said opening;
- wherein said steps of forming a passivating layer and executing a directional etch are carried out repeatedly in sequence so as to form a trench through said opening;
- wherein the process further comprises the step of forming a tapered portion of said trench, having a transverse dimension decreasing as a distance from said surface increases.
A semiconductor body, having a surface and comprising at least one trench open at said surface, wherein said trench includes at least one spacing portion, having a width (W′) that on average increases as a distance from said surface increases;
- wherein said trench comprises at least one tapered portion, which has a width that decreases as a distance from said surface increases.
A process for digging a deep trench in a body of semiconductor material, the semiconductor material having a surface and a mask formed on the surface, the mask having at least one opening and the method comprising:
- conformally forming a passivating layer on the mask and on portions of the semiconductor body exposed within each opening;
- performing a directional etch to remove the passivating layer from the portions of the semiconductor body exposed within each opening and to remove the semiconductor body through the opening to form a trench;
- and
- performing a polymerizing plasma etch to remove portions of the semiconductor body in the trench and form each deep trench.
A semiconductor body having a surface and including a plurality of trenches open at the surface, each trench having a first portion with a width that increases as a function of increasing depth of the trench from the surface and each trench having a second portion with a width that decreases as a function of increasing depth of the trench from the surface.
Dependencies are inferred from the claim text.