Fairchild Semiconductor Corporation

Fairfield Semiconductor Corporation

Gordon K Madson

Joelle Sharp

Christopher Boguslaw Kocon

Dean E Probst

Steven Paul Sapp

Ashok Challa

Bruce Douglas Marchant

James J Murphy

Alan Elbanhawy

Becky Losee

Robert Herrick

Peter H Wilson

Babak S Sani

Debra S Woolsey

A method can include forming a drift region, forming a well region above the drift region, and forming an active trench extending through the well region and into the drift region. The method can include forming a first source region in contact with a first sidewall of the active trench and a second source region in contact with a second sidewall of the active trench. The method also includes forming a charge control trench where the charge control trench is aligned parallel to the active trench and laterally separated from the active trench by a mesa region, and where the portion of the well region is in contact with the charge control trench and excludes any source region. The method also includes forming an oxide along a bottom of the active trench having a thickness greater than a thickness of an oxide along the first sidewall of the active trench.

Methods related to power semiconductor devices with thick bottom oxide layers

A shielded gate field effect transistor includes a trench extending into a semiconductor region. A shield electrode is in a lower portion of the trench, and is insulated from the semiconductor region by a shield dielectric. The shield dielectric comprises first and second dielectric layers, the first dielectric layer extending between the second dielectric layer and the semiconductor region. The second dielectric layer comprises a material which during oxidation process inhibits growth of oxide along surfaces of the semiconductor region covered by the second dielectric layer. An inter-electrode dielectric overlies the shield electrode, and a gate dielectric lines upper trench sidewalls. A gate electrode is in an upper portion of the trench over the inter-electrode dielectric.

Method and structure for shielded gate trench FET

A method of manufacturing a semiconductor device having a charge control trench and an active control trench with a thick oxide bottom includes forming a drift region, a well region extending above the drift region, an active trench extending through the well region and into the drift region, a charge control trench extending deeper into the drift region than the active trench, an oxide film that fills the active trench, the charge control trench and covers a top surface of the substrate, an electrode in the active trench, and source regions. The method also includes etching the oxide film off the top surface of the substrate and inside the active trench to leave a substantially flat layer of thick oxide having a target thickness at the bottom of the active trench.

Methods of making power semiconductor devices with thick bottom oxide layer

A field effect transistor is formed as follows. Openings are formed in a masking layer extending over a surface of a silicon region. A trench is formed in the silicon region through each opening in the masking layer. A layer of silicon is formed along sidewalls and bottom of each trench and along masking layer sidewalls which define each opening. The masking layer is removed to expose surface areas of the silicon region underlying the masking layer and to expose sidewalls of the layer of silicon to thereby form contact openings over the surface of the silicon region. A contact layer is formed to electrically contact the exposed surface areas of the silicon region and the exposed sidewalls of the layer of silicon.

Structure and method for forming a minimum pitch trench-gate FET with heavy body region

A method of forming a trench in a substrate or in an epitaxial layer, previously grown over the semiconductor substrate, wherein an anneal step, using hydrogen gas results in rounded corners without the need for a rounding etch or any other processing steps to round the corners.

Hydrogen anneal for creating an enhanced trench for trench MOSFETS

A method of manufacturing a trench structure for a trench MOSFET, including the steps of providing a semiconductor substrate having a major surface, forming a dielectric pillar on the substrate major surface (the dielectric pillar extending substantially perpendicularly from the major surface of the substrate), selectively forming a semiconductor layer around the dielectric pillar, and removing a predetermined length of the dielectric pillar to create a trench in the substrate, the trench defined by sidewalls and a bottom. The method permits the controlled formation of a dielectric plug at the bottom of the trench, the plug having predetermined dimensions.

Method of manufacturing a trench MOSFET using selective growth epitaxy

A method of creating a thermally grown oxide of any thickness at the bottom of a silicon trench. A dielectric (e.g. oxide) pillar of a predetermined thickness is formed on a semiconductor substrate. A selective epitaxial growth (SEG) process is used to form an epitaxial layer around and over the oxide pillars. A trench is patterned and etched through the SEG layer and in alignment with the oxide pillar such that the trench terminates at the top of the oxide pillar.

Trench MOSFET formed using selective epitaxial growth

A method of increasing trench density for semiconductor devices such as, for example, trench MOSFETs. Trenches are formed in a substrate with mesas interposed between the trenches. The initial width of the mesas are made less than target width so that a reduction in trench pitch can be realized. After a silicon layer is grown inside the trenches, the width of the mesas is increased to a final width that is two times the thickness of the silicon layer. The thickness of the silicon layer is precalculated so that it is of sufficient thickness to ensure compliance with the target mesa width.

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Herriman, UT, United States of America

Gordon K Madson