Semiconductor structures with isolated ohmic trenches and stand-alone isolation trenches and related method

摘要

A method of forming a semiconductor structure in a semiconductor-on-insulator (SOI) substrate and semiconductor structure so formed are provided. The SOI substrate includes a semiconductor layer; a bulk semiconductor region underlying the semiconductor layer; and an insulation layer between the two. The method includes substantially simultaneously forming a first opening and a second opening extending from the semiconductor layer to the conductive region; introducing an insulating material to the side walls of the first opening; at least partially filling the first opening with a semiconductor material to provide an ohmic contact trench; and at least partially filling the second opening with an insulating material to form a device isolation trench. Insulating regions, for example, shallow trench isolation (STI) regions, may be formed about the device isolation trench and the ohmic contact trench. Semiconductor structures are also provided. The benefits of combining the features of SOI and STI structures are provided.

主权项

1. A method of forming a semiconductor structure using a semiconductor-on-insulator (SOI) substrate, the SOI substrate comprising:
a semiconductor layer; a bulk semiconductor region underlying the semiconductor layer; and an insulation layer between the semiconductor layer and the bulk semiconductor region;the method comprising:
forming a first opening having sidewalls and a second opening having sidewalls, each of the first opening and the second opening extending from a top surface of the semiconductor layer through the semiconductor layer and through the insulation layer to the bulk semiconductor region, wherein a lateral width of the first opening is greater than a lateral width of the second opening; forming an insulating material in the first and second openings to coat the sidewalls of the first opening and at least fill the entirety of the second opening to form a device isolation trench therein, the insulating material being adapted to provide electrical insulation to at least a portion of the sidewalls of the first opening, wherein at least a portion of the first opening is free of insulating material therein; and filling the portion of the first opening with a semiconductor material to provide an ohmic contact trench in contact with the bulk semiconductor region, wherein the formed insulating material in the second opening prevents the semiconductor material from entering the second opening during the filling.