Radiation hardened semiconductor device
AssigneeAeroflex Colorado Springs Inc.
InventorsRichard L. Woodruff, Scott M. Tyson, John T. Chaffee, David B. Kerwin
Life of this patent
Estimating the term…
Abstract
A method for manufacturing a radiation hardened semiconductor device, having defined active region and isolation region. The isolation region containing an isolation material and active region containing a transition region between active and isolation region, sometimes denoted a bird's beak region. Wherein the transition region is doped with germanium and boron, to prevent formation of leakage paths between active devices, or within an active device. The doped area can be further limited to that area of the transition region that is adapted to be covered by a gate material, such as polysilicon.
Claims58
A method of forming a radiation hardened semiconductor device having a semiconductor substrate having an active region and an isolation region therein, the active region having an upper surface and the isolation region having an upper surface, the active region further including a bird's beak region therein, comprising:
- implanting the isolation region and the active region with a first dopant;
- applying a first implant blocking layer on the upper surface of the isolation region and the upper surface of the active region;
- removing a section of said first implant blocking layer and exposing the upper surface of the isolation region and the bird's beak region;
- implanting the isolation region and the bird's beak region with a second dopant;
- and
- removing said first implant blocking layer.
A method of manufacturing a radiation hardened semiconductor device including a substrate and epitaxial layer, wherein the epitaxial layer is doped with a first dopant, the epitaxial layer including an active region and an isolation region therein, the active region including an upper surface and the isolation region including an upper surface, the active region further including a bird's beak region therein, comprising:
- depositing a first implant blocking layer on the upper surface of the isolation region and the upper surface of the active region;
- removing a section of said first implant blocking layer and exposing the upper surface of the isolation region and the bird's beak region;
- implanting the isolation region and the bird's beak region with a second dopant;
- and
- removing said first implant blocking layer.
A method of forming a radiation hardened semiconductor device having a having a semiconductor substrate, the semiconductor substrate having an upper surface, the steps comprising:
- depositing a masking layer on the upper surface;
- removing a portion of said masking layer to expose an isolation region, wherein a remaining portion of said masking layer defines an active region;
- implanting an upper surface of the isolation region with a first dopant;
- oxidizing said isolation region to form a field oxide, wherein a portion of said first dopant is incorporated into said field oxide, and wherein a portion of said field oxide underlies the active region, said portion of said field oxide known as a bird's beak region;
- removing said remaining portion of said masking layer;
- applying a first implant blocking layer on said upper surface of the isolation region and an upper surface of the active region;
- removing a section of said first implant blocking layer and exposing said upper surface of said isolation region and said bird's beak region;
- implanting said isolation region and said bird's beak region with a second dopant;
- and
- removing said first implant blocking layer.
The method of claim 551 prior to the step of applying said first implant blocking layer, further comprising the step of implanting said isolation region and said active region with said first dopant.
Dependencies are inferred from the claim text.