Semiconductor device and method of providing regions of low substrate capacitance

A method of making a semiconductor structure (1), comprising the steps of:

• forming a pillar (15) of semiconductor material 10 under a isolation region of a semiconductor substrate 5 and capping the pillar with a first dielectric material (20) to form a void (16).

A semiconductor device (1), comprising:

• an electrical component (25);
• and
• a semiconductor substrate (10) having a isolation region (5) for forming the electrical component, where the isolation region includes a silicon pillar (15) extending into the semiconductor substrate.

A method of making a semiconductor device (1), comprising the steps of:

• forming silicon pillar (15, 27) under a isolation region (5) of a semiconductor substrate (10) wherein the silicon pillar is capped with a first dielectric material (20) to form a void (16);
• and
• forming an electrical component (25) on the isolation region.

A semiconductor structure (1), comprising:

• a semiconductor substrate (10) having a recessed region formed with a pillar;
• and
• a dielectric material disposed over the recessed region and capping the pillar to form a void between the pillar and a sidewall of the recessed region.

A method of making a semiconductor structure, comprising the steps of:

• oxidizing sidewalls of cavities in a semiconductor material to form a continuous oxide layer between adjacent cavities;
• and
• etching the continuous oxide layer to leave a pillar of the semiconductor material.