Microwave integrated circuits including gallium-nitride devices on silicon

A method of forming an integrated circuit, comprising:

• forming a first integrated device over a first semiconductor structure in a first region of the integrated circuit;
• forming a second integrated device over a second semiconductor structure in a second region of the integrated circuit;
• etching a cavity in a third region of the of the integrated circuit located between the first region and the second region;
• filling the cavity with an insulating material;
• and
• forming a passive component over the insulating material in the third region of the integrated circuit, wherein:
• the passive component comprises a network of passive components;
• and
• the network of passive components comprises at least one capacitor and at least one inductor.

A method of forming an integrated circuit, comprising:

• forming a first integrated device over a first semiconductor structure in a first region of the integrated circuit;
• forming a second integrated device over a second semiconductor structure in a second region of the integrated circuit;
• etching a cavity in a third region of the of the integrated circuit located between the first region and the second region;
• filling the cavity with an insulating material;
• and
• forming a passive component over the insulating material in the third region of the integrated circuit, wherein, after the etching, the integrated circuit comprises a semiconductor pedestal in the third region.

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

• forming a layer of gallium nitride material over a semiconductor substrate of the integrated circuit;
• etching a cavity in a third region of the of the integrated circuit located between a first region and a second region of the integrated circuit;
• filling the cavity with an insulating material;
• forming a first integrated device over a first semiconductor structure in the first region of the integrated circuit;
• forming a second integrated device over a second semiconductor structure in the second region of the integrated circuit;
• grinding a back side of a semiconductor substrate of the integrated circuit to electrically isolate the first semiconductor structure from the second semiconductor structure;
• and
• forming a ground plane over the back side of the semiconductor substrate.