Method of undercut anisotropic etching of semiconductor material

Claim 2

In a method for undercut anisotropic etching of an etch stopped layer portion on a (110) face of diamond cubic semiconductor material, to form beam or bridge structures, said etch stopped layer portion which is to be undercut having a pair of opposing side edges, the steps of: orienting said pair of opposing side edges of the etch stopped layer portion which is to be undercut at an angle to the most nearly parallel one of the {111} traces on the (110) face being etched, so that said oriented side edges will be undercut from the sides; and contacting the (110) face being etched with an isotropic etchant for the semiconductive material so as to essentially completely undercut the etch stopped layer portion from both of said side edges in a direction toward the opposing side edge.

Claim 3

In a method for undercut anisotropic etching of an etch stopped layer portion on a (110) face of diamond cubic semiconductor material, to form beam or bridge structures, said etch stopped layer portion which is to be undercut having a pair of opposing side edges, the steps of: orienting said pair of opposing side edges of the etch stopped layer portion which is to be undercut at an angle to the most nearly parallel one of the {111} traces on the (110) face being etched, so that said oriented side edges will be undercut from the sides; slotting the etch stopped layer portion which is to be undercut with at least one elongated slot therethrough to the underlying material which is to be etched; and contacting the (110) face being etched with anisotropic etchant for the semiconductive material so as to essentially completely undercut the etch stopped layer portion from both of said side edges in a direction toward the opposing side edge.

Claim 4

In a method for undercut anisotropic etching of an etch stopped layer portion on a (110) face of diamond cubic semiconductor material, to form beam or bridge structures, said etch stopped layer portion which is to be undercut having a pair of opposing side edges, the steps of: orienting said pair of opposing side edges of the etch stopped layer portion which is to be undercut at an angle to the most nearly parallel one of the {111} traces on the (110) face being etched, so that said oriented side edges will be undercut from the sides; slotting the etch stopped layer portion which is to be undercut with at least one elongated slot therethrough to the underlying material which is to be etched; and contacting the (110) face being etched with anisotropic etchant for the semiconductive material so as to essentially completely undercut the etch stopped layer portion from both of said side edges in a direction toward the opposing side edge.

Claim 5

In a method for undercut anisotropic etching of an etch stopped layer portion on a (110) face of diamond cubic semiconductor material to form beam or bridge structures, said etch stopped layer portion which is to be undercut having a pair of opposing side edges, the steps of: orienting said pair of opposing side edges of the etch stopped layer portion which is to be undercut at an angle to the most nearly parallel one of the {111} traces on the (110) face being etched, so that said oriented edges will be undercut from the sides; said etch stopped layer portion which being to be undercut is of generally quadrilateral shape such that when undercut it has a second pair of opposed side edges disposed generally parallel to the most nearly parallel ones of the {111} traces on the face being etched, whereby said undercut layer is joined along both of said second pair of side edges to lip portions of semiconductive material which is not to be undercut by said etchant for supporting said undercut portion of said etch stopped layer along said joined side edges; and contacting the (110) face being etched with anisotropic etchant for the semiconductive material so as to essentially completely undercut the etch stopped layer portion from both of said side edges in a direction toward the opposing side edge.

Claim 6

In a method for undercut anisotropic etching of an etch stopped layer portion on a (110) face of diamond cubic semiconductor material to form beam or bridge structures, said etch stopped layer portion which is to be undercut having a pair of opposing side edges, the steps of: orienting said pair of opposing side edges of the etch stopped layer portion which is to be undercut at an angle to the most nearly parallel one of the {111} traces on the (110) face being etched, so that said oriented edges will be undercut from the sides; said etch stopped layer portion which being to be undercut is of generally quadrilateral shape such that when undercut it has a second pair of opposed side edges disposed generally parallel to the most nearly parallel ones of the {111} traces on the face being etched, whereby said undercut layer is joined along both of said second pair of side edges to lip portions of semiconductive material which is not to be undercut by said etchant for supporting said undercut portion of said etch stopped layer along said joined side edges; and contacting the (110) face being etched with anisotropic etchant for the semiconductive material so as to essentially completely undercut the etch stopped layer portion from both of said side edges in a direction toward the opposing side edge.

Claim 7

The method of claim 3 including the step of providing said etch stopped layer portion which is to be undercut on opposite major faces of a semiconductive wafer, and contacting both major faces with the etchant to undercut both of said etch stop layer portions on opposite sides of the wafer.

Claim 8

The product of the method of claim 1.

Claim 9

The product of the method of claim 3.

Claim 10

The product of the method of claim 4.

Claim 11

In a method for undercut anisotropic etching an etch stopped layer portion on a face of diamond cubic semiconductor material, to form beam or bridge structures, said etch stopped layer portion which is to be undercut having a pair of opposing side edges, the steps of: orienting said pair of opposing side edges of the etch stopped layer portion which is to be undercut at an angle to the most nearly parallel one of the {111} traces on the face being etched, so that said oriented side edges will be undercut from the sides; terminating said pair of opposing side edges which are to be undercut on a common {111} trace on the major face of the wafer such that the undercut etch stops on the common {111} trace on the major face of the wafer whereby said undercut layer portion is supported and terminated by a non-undercut lip portion of semiconductive material defined by a common {111} trace on the major face of the wafer; and contacting the face being etched with anisotropic etchant for the semiconductor material so as to undercut the etch stop layer portion from both of said side edges in the direction toward the opposing edge and to essentially completely undercut the etch stopped layer to form the beam or bridge structure terminated on a common {111} trace.

Claim 12

In a method for undercut anisotropic etching an etch stopped layer portion on a face of diamond cubic semiconductor material, to form beam or bridge structures, said etch stopped layer portion which is to be undercut having a pair of opposing side edges, the steps of: orienting said pair of opposing side edges of the etch stopped layer portion which is to be undercut at an angle to the most nearly parallel one of the {111} traces on the face being etched, so that said oriented side edges will be undercut from the sides; terminating said pair of opposing side edges which are to be undercut on a common {111} trace on the major face of the wafer such that the undercut etch stops on the common {111} trace on the major face of the wafer whereby said undercut layer portion is supported and terminated by a non-undercut lip portion of semiconductive material defined by a common {111} trace on the major face of the wafer; and contacting the face being etched with anisotropic etchant for the semiconductor material so as to undercut the etch stop layer portion from both of said side edges in the direction toward the opposing edge and to essentially completely undercut the etch stopped layer to form the beam or bridge structure terminated on a common {111} trace.

Claim 13

The method of claim 8 wherein said etch stopped layer portion which is to be undercut is of generally quadrilateral shape such that when undercut, it has a second pair of opposed side edges disposed generally parallel to the most nearly parallel ones of the {111} traces on the face being etched, whereby said undercut layer is joined along both of said second pair of side edges to lip portions of semiconductive material which is not to be undercut by said etchant for supporting said undercut portion of said etch stopped layer along said joined side edges.

Claim 14

The product of the method of claim 8.

Claim 15

In a method for undercut anisotropic etching of an etch stopped layer portion on a face of diamond cubic semiconductor material to form beam or bridge structures, said etch stopped layer portion which is to be undercut having a pair of opposing side edges, the steps of: orienting said pair of opposing side edges of the etch stopped layer portion which is to be undercut at an angle to the most nearly parallel one of the {111} traces on the face being etched, so that said oriented side edges will be undercut from the side; slotting the etch stopped layer portion which is to be undercut with an array of lines of elongated generally parallel interrupted side-by-side slots therethrough to the underlying material which is to be etched; said side-by-side interrupted slots being elongated in a direction at a substantial angle to the {111} traces on the major face of the wafer and the lines of slots being axially offset with respect to each other such that the interrupted portions of one line of slots is located generally in transverse registration with the centers of the slots in the adjacent line of parallel slots, whereby undercut etch time is reduced in practice; and contacting the face being etched with anisotropic etchant for the semiconductive material so as to undercut the etch stopped layer portion from both of said side edges in a direction toward the opposing side edge and on the inside walls of the slots toward the adjacent slots to essentially completely undercut the etched stopped layer to form the beam or bridge structure.

Claim 16

In a method for undercut anisotropic etching of an etch stopped layer portion on a face of diamond cubic semiconductor material to form beam or bridge structures, said etch stopped layer portion which is to be undercut having a pair of opposing side edges, the steps of: orienting said pair of opposing side edges of the etch stopped layer portion which is to be undercut at an angle to the most nearly parallel one of the {111} traces on the face being etched, so that said oriented side edges will be undercut from the side; slotting the etch stopped layer portion which is to be undercut with an array of lines of elongated generally parallel interrupted side-by-side slots therethrough to the underlying material which is to be etched; said side-by-side interrupted slots being elongated in a direction at a substantial angle to the {111} traces on the major face of the wafer and the lines of slots being axially offset with respect to each other such that the interrupted portions of one line of slots is located generally in transverse registration with the centers of the slots in the adjacent line of parallel slots, whereby undercut etch time is reduced in practice; and contacting the face being etched with anisotropic etchant for the semiconductive material so as to undercut the etch stopped layer portion from both of said side edges in a direction toward the opposing side edge and on the inside walls of the slots toward the adjacent slots to essentially completely undercut the etched stopped layer to form the beam or bridge structure.

Claim 17

The product of the method of claim 11.