Photonic semiconductor-on-insulator (SOI) substrate and method for forming the photonic SOI substrate

A method for forming a semiconductor-on-insulator (SOI) structure, the method comprising:

• forming a first dielectric layer on a semiconductor base layer;
• forming a first semiconductor device layer comprising a first semiconductor material over an etch stop layer (ESL);
• forming a second dielectric layer over the first semiconductor device layer;
• providing a cleaning solution to a first surface of the first dielectric layer and a first surface of the second dielectric layer to remove particles from the first surface of the first dielectric layer and the first surface of the second dielectric layer;
• bonding the first surface of the first dielectric layer and the first surface of the second dielectric layer in an environment having a substantially low pressure;
• removing the ESL from over the first semiconductor device layer;
• forming a first index guiding layer comprising a second semiconductor material, different from the first semiconductor material, over the first semiconductor device layer;
• forming a second semiconductor device layer comprising a third semiconductor material, different from the second semiconductor material, over the first index guiding layer, wherein a distance between a top of the second semiconductor device layer and a bottom of the first semiconductor device layer varies between a maximum distance and a minimum distance, different than the maximum distance, along the second semiconductor device layer;
• and
• performing a planarization process on the second semiconductor device layer to reduce the maximum distance between the top of the second semiconductor device layer and the bottom of the first semiconductor device layer.

A semiconductor-on-insulator (SOI) structure comprising:

• a semiconductor base layer;
• a first dielectric layer over the semiconductor base layer;
• a second dielectric layer over the first dielectric layer;
• and
• a semiconductor device structure over the second dielectric layer, the semiconductor device structure comprising a first semiconductor device layer and a second semiconductor device layer over the first semiconductor device layer, wherein a thickness of the semiconductor device structure varies between a maximum thickness and a minimum thickness, different than the maximum thickness, and wherein a difference the maximum thickness and the minimum thickness is less than 5% of the maximum thickness.