Method of forming trench semiconductor device having multiple trench depths

A method of forming a semiconductor device comprising:

• providing a region of semiconductor material comprising a semiconductor layer adjoining a semiconductor substrate, the semiconductor layer defining a major surface, wherein the semiconductor layer has a first dopant concentration and the semiconductor substrate has a second dopant concentration greater than the first dopant concentration;
• in a single step:
• forming a termination trench extending from a first portion of the major surface into the region of semiconductor material, wherein the first trench extends to a first depth, and wherein the termination trench has a first width;
• and
• forming a plurality of active trenches each extending from a second portion of the major surface into the region of semiconductor material to a second depth, wherein each active trench has a second width less than the first width, and wherein the first depth is greater than the second depth to define a trench depth difference, and wherein one of the active trenches is disposed in the region of semiconductor material as a closest trench structure to the termination trench;
• forming a first conductive material within each active trench and separated from the region of semiconductor material by a dielectric region;
• and
• forming a second conductive material having a first portion adjoining a third portion of the major surface, wherein the first portion of the second conductive material is configured to provide a Schottky barrier.

A method of forming a Schottky semiconductor device comprising:

• providing a region of semiconductor material comprising a semiconductor layer adjacent a semiconductor substrate, the semiconductor layer defining a major surface, wherein the semiconductor layer has a first dopant concentration and the semiconductor substrate has a second dopant concentration greater than the first dopant concentration;
• forming a termination trench extending from a first portion of the major surface into the region of semiconductor material, wherein:
• the termination trench extends to a first depth;
• and
• the termination trench has a first width;
• forming an active trench extending from a second portion of the major surface into the region of semiconductor material to a second depth, wherein:
• the active trench has a second width less than the first width;
• the first depth is greater than the second depth to provide a trench depth difference;
• a portion of the region of semiconductor material is laterally interposed between the active trench and the termination trench in a cross-sectional view;
• and
• the portion of the region of semiconductor material is devoid of trench structures so that the active trench is a closest trench structure to the termination trench in the cross-sectional view;
• forming a first conductive material within the second trench and separated from the region of semiconductor material by a dielectric region;
• and
• forming a second conductive material adjoining a third portion of the major surface, wherein the second conductive material is configured to provide a Schottky barrier.