Hrl Laboratories, LLC

Other

The Boeing Company

Ivan Milosavljevic

Adele E Schmitz

Michael T Antcliffe

Ming Hu

Miroslav Micovic

Keisuke Shinohara

Andrea Corrion

Dean C Regan

David T Chang

Peter J Willadsen

Colleen M Butler

Hector L Bracamontes

Michael Delaney

Bruce T Holden

Lorna Hodgson

Joel C Wong

Yan Tang

Antonio Mei

Amanda Simpson

A method, apparatus, and system for processing a material stack. A hydrogen silsesquioxane layer is deposited on the material stack. A diffusion barrier layer is deposited on the hydrogen silsesquioxane layer to form a bilayer. The diffusion barrier layer comprises a material having a thickness that increases an amount of time before the hydrogen silsesquioxane layer ages to change a dose in an electron beam needed to expose the hydrogen silsesquioxane layer for a selected feature geometry with a desired width. The electron beam is directed through a surface of the bilayer to form an exposed portion of the bilayer. The electron beam applies the dose that is selected based on a pattern density of features for the material stack to have a desired level of exposure of the hydrogen silsesquioxane layer for the selected feature geometry. The hydrogen silsesquioxane layer is developed. The exposed portion remains on material stack.

Electron beam lithography with a bilayer resist

A method of forming a slanted field plate including forming epitaxy for a FET on a substrate, forming a wall near a drain of the FET, the wall comprising a first negative tone electron-beam resist (NTEBR), depositing a dielectric over the epitaxy and the wall, the wall causing the dielectric to have a step near the drain of the FET, depositing a second NTEBR over the dielectric, wherein surface tension causes the deposited second NTEBR to have a slanted top surface between the step and a source of the FET, etching anisotropically vertically the second NTEBR and the dielectric to remove the second NTEBR and to transfer a shape of the slanted top surface to the dielectric, and forming a gatehead comprising metal on the dielectric between the step and the source of the FET, wherein the gatehead forms a slanted field plate.

Method of fabricating slanted field-plate GaN heterojunction field-effect transistor

A method for fabricating a gate structure for a field effect transistor having a buffer layer on a substrate, a channel layer and a barrier layer over the channel layer includes forming a gate of a first dielectric, forming first sidewalls of a second dielectric on either side and adjacent to the gate, selectively etching into the buffer layer to form a mesa for the field effect transistor, depositing a dielectric layer over the mesa, planarizing the dielectric layer over the mesa to form a planarized surface such that a top of the gate, tops of the first sidewalls, and a top of the dielectric layer over the mesa are on the same planarized surface, depositing metal on the planzarized surface, annealing to form the gate into a metal silicided gate, and etching to remove excess non-silicided metal.

Gate metallization methods for self-aligned sidewall gate GaN HEMT

A method for fabricating a gate structure for a field effect transistor having a buffer layer on a substrate, a channel layer and a barrier layer over the channel layer includes forming a gate including silicon, forming first sidewalls of a first material on either side and adjacent to the gate, selectively etching into the buffer layer to form a mesa for the field effect transistor, depositing a material layer over the mesa, planarizing the material layer over the mesa to form a planarized surface such that a top of the gate, tops of the first sidewalls, and a top of the material layer over the mesa are on the same planarized surface, depositing metal on the planzarized surface, annealing to form the gate into a metal silicided gate, and etching to remove excess non-silicided metal.

In various embodiments, a tiered gate structure transistor is provided including a source, a drain, and a gate between the source and the drain. The tiered gate structure transistor including a gate foot having a top portion and sidewalls. A gate head is attached to the top portion of the gate foot. A passivation layer extends along and directly contacts an uppermost surface of the source, and extends along and directly contacts an uppermost surface of the drain, the passivation layer surrounds the sidewalls of the gate foot such that the top portion is not covered by the passivation layer and such that the passivation layer surrounding the sidewalls supports the gate head.

Passivated tiered gate structure transistor

In one embodiment, a tiered gate device is provided including a source, a drain, and a gate foot therebetween. A gate head is attached to the gate foot. A source extension extends from on an uppermost surface of the source toward the gate foot along the substrate. In some embodiments a drain extension extends from on and uppermost surface of the drain toward the gate foot along the substrate.

Tiered gate device with source and drain extensions

In one embodiment, a tiered gate structure is provided having a substrate including a source, a drain and a gate thereon. The gate includes an elongated gate foot having a first deposition gate material extending from the substrate, the elongated gate foot having a top portion distal from the substrate. The gate head has a second deposition gate material and includes an elongated portion extending downward from the gate head to connect to the top portion of the elongated gate foot.

Tiered gate structure devices

A method for fabricating a tiered structure includes forming a gate on a semiconductor substrate. Formation of the gate includes depositing a gate foot using a gate foot mask having an opening through it to define the gate foot over the substrate. After forming the gate foot, the gate foot mask is stripped and a passivation layer is formed over the gate foot and the substrate. A gate head mask is formed over the gate foot with the gate head mask exposing a portion of the passivation layer on a top portion of the gate foot. The portion of the passivation layer on the top portion of the gate foot is removed to expose the top portion of the gate foot. A gate head is formed on the top portion of the gate foot using the gate head mask. A lift-off process is performed, removing the gate head mask.

Passivated tiered gate structure transistor and fabrication method

In one embodiment, a tiered gate device is provided including a source, a drain, and a gate foot therebetween. A gate head is attached to the gate foot. A source extension extends from on the source toward the gate foot along the substrate. In some embodiments a drain extension extends from on the drain toward the gate foot along the substrate.

In one implementation, a method for fabricating a tiered structure is provided, which includes forming a source and a drain on a substrate with a gate formed therebetween. Formation of the gate includes depositing a gate foot using a gate foot mask having an opening through it to define the gate foot over the substrate. After forming the gate foot, the gate foot mask is stripped. A gate head mask is formed over the gate foot with the gate head mask exposing a top portion of the gate foot. A gate head is formed on the top portion of the gate foot using the gate head mask. A lift-off process is performed, removing the gate head mask.

Growing community of inventors

Thousand Oaks, CA, United States of America

Ivan Milosavljevic