Forming Inter-Device STI Regions and Intra-Device STI Regions Using Different Dielectric Materials

A method of forming an integrated circuit structure, the method comprising:

• providing a semiconductor substrate;
• etching the semiconductor substrate to form first recesses;
• filling the first recesses with a first dielectric material having a first k value to form first shallow trench isolation (STI) regions;
• removing portions of the first STI regions to form second recesses;
• filling the second recesses with a second dielectric material having a second k value to form second STI regions, the first k value being different from the second k value;
• recessing one of the first STI regions and the second STI regions to form a semiconductor fin, the semiconductor fin being over a top surface of the one of the first STI regions and the second STI regions;
• forming a gate dielectric on a top surface and sidewalls of the semiconductor fin;
• and
• forming a gate electrode over the gate dielectric.

A method of forming an integrated circuit structure, the method comprising:

• providing a semiconductor substrate comprising a first portion in a an intra-device region and a second portion in an inter-device region;
• forming an intra-device shallow-trench isolation (STI) region over the semiconductor substrate, the intra-device STI region being formed of a low-k dielectric material having a first k value;
• forming a first FinFET comprising:
• forming a semiconductor fin adjacent and over the intra-device STI region;
• forming a gate dielectric on the semiconductor fin;
• and
• forming a gate electrode over the gate dielectric, the gate electrode comprising a portion directly over the intra-device STI region;
• and
• forming an inter-device STI region over the semiconductor substrate, the inter-device STI region being formed of a non-low-k dielectric material having a second k value, the second k value being greater than the first k value.