Customized shield plate for a field effect transistor
First Claim
1. A transistor, comprising:
- a semiconductor substrate including a surface layer extending from an upper surface of the semiconductor substrate to a surface depth;
a gate dielectric overlying a channel region of the surface layer;
a gate electrode overlying the gate dielectric, the gate electrode including a first sidewall and a second sidewall;
a source region comprising a portion of the surface region extending between the channel region and a source contact region;
a drift region comprising a portion of the surface region extending between the channel region and a drain region;
a shield interlevel dielectric (ILD) overlying at least a portion of an upper surface of the gate electrode, the second sidewall, and a portion of the drift region;
a shield plate comprising an electrically conductive layer overlying at least a portion of the shield ILD, the shield plate defining a shield plate edge overlying the drift region, wherein the shield plate edge comprises a customized shield plate edge wherein a displacement between the customized shield plate edge and the second sidewall varies along a length of the second sidewall.
31 Assignments
0 Petitions
Accused Products
Abstract
A customized shield plate field effect transistor (FET) includes a semiconductor layer, a gate dielectric, a gate electrode, and at least one customized shield plate. The shield plate includes a conductive layer overlying a portion of the gate electrode, one of the gate electrode sidewalls, and a portion of the substrate adjacent to the sidewall. The shield plate defines a customized shield plate edge at its lateral boundary. A distance between the customized shield plate edge and the sidewall of the gate electrode varies along a length of the sidewall. The customized shield plate edge may form triangular, curved, and other shaped shield plate elements. The configuration of the customized shield plate edge may reduce the area of the resulting capacitor and thereby achieve lower parasitic capacitance associated with the FET. The FET may be implemented as a lateral diffused MOS (LDMOS) transistor suitable for high power radio frequency applications.
57 Citations
17 Claims
-
1. A transistor, comprising:
-
a semiconductor substrate including a surface layer extending from an upper surface of the semiconductor substrate to a surface depth; a gate dielectric overlying a channel region of the surface layer; a gate electrode overlying the gate dielectric, the gate electrode including a first sidewall and a second sidewall; a source region comprising a portion of the surface region extending between the channel region and a source contact region; a drift region comprising a portion of the surface region extending between the channel region and a drain region; a shield interlevel dielectric (ILD) overlying at least a portion of an upper surface of the gate electrode, the second sidewall, and a portion of the drift region; a shield plate comprising an electrically conductive layer overlying at least a portion of the shield ILD, the shield plate defining a shield plate edge overlying the drift region, wherein the shield plate edge comprises a customized shield plate edge wherein a displacement between the customized shield plate edge and the second sidewall varies along a length of the second sidewall. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
-
-
15. A semiconductor device, comprising:
-
a semiconductor layer including a surface layer extending from an upper surface of the semiconductor layer to a surface depth; a gate dielectric overlying the surface layer; a gate electrode including a first sidewall and a second sidewall defining lateral boundaries of a channel region of the surface layer; a shield interlevel dielectric (ILD) including a portion overlying at least a portion of an upper surface of the gate electrode, the first sidewall, and a drift region of the surface region, the drift region being adjacent the channel region; a customized shield plate comprising a conductive layer overlying at least a portion of the shield ILD, the shield plate defining a customized shield plate edge overlying the drift region, wherein a portion of the customized shield plate edge is non parallel to the second sidewall. - View Dependent Claims (16, 17)
-
Specification