Bulk Semiconductor Substrate Configured to Exhibit Semiconductor-on-Insulator Behavior

A semiconductor-on-insulator like structure comprising:

• a bulk substrate;
• a dual-isolation structure that includes:
• a first isolation trench defined in the bulk substrate, wherein the first isolation trench is configured to define a channel region of the bulk substrate, the first isolation trench includes a first isolation trench portion and a second isolation trench portion disposed over the first isolation trench portion, and:
• a first isolation material fills the first isolation trench portion of the first isolation trench;
• and
• an epitaxial material fills the second isolation trench portion of the first isolation trench, wherein the epitaxial material is disposed on the first isolation material, and
• a second isolation trench defined in the bulk substrate, wherein the second isolation trench defines an active region that includes the channel region, and further wherein a second isolation material fills the second isolation trench;
• and
• an amorphous layer disposed in the bulk substrate underlying the first isolation trench and the channel region, wherein a resistance of the amorphous layer is greater than a resistance of the bulk substrate.

A method for fabricating an integrated circuit device, such that a bulk substrate of the integrated circuit device exhibits semiconductor-on-insulator behavior, the method comprising:

• forming a first isolation trench in a bulk substrate, wherein the first isolation trench defines a channel region of the bulk substrate;
• increasing a resistance of a portion of the bulk substrate underlying the first isolation trench and the channel region of the bulk substrate;
• filling a first portion of the first isolation trench with a first insulator material;
• filling a second portion of the first isolation trench with a semiconductor material;
• forming a second isolation trench in the bulk substrate, wherein the second isolation trench defines an active region that includes the channel region;
• and
• filling the second isolation trench with a second insulator material.