Method for forming semiconductor-on-insulator (SOI) substrate by cleaving a multilayer structure along voids to separate a substrate

A method for forming an SOI substrate, comprising:

• receiving a recycle substrate, wherein a first multilayered structure is formed over the recycle substrate;
• forming a trench in the first multilayered structure;
• performing a lateral etching to remove portions of sidewalls of the trench to form a recess in the first multilayered structure;
• sealing the trench and the recess with an epitaxial layer to form a potential cracking interface in the first multilayered structure;
• forming a second multilayered structure over the first multilayered structure, wherein the second multilayered structure comprises at least a device layer;
• receiving a carrier substrate, wherein an insulator layer is formed over the carrier substrate;
• bonding the device layer over the recycle substrate to the insulator layer over the carrier substrate;
• cleaving the first multilayered structure along the potential cracking interface to separate the recycle substrate from the second multilayered structure, the insulator layer and the carrier substrate;
• and
• exposing the device layer.

A method for forming an SOI substrate, comprising:

• receiving a substrate;
• sequentially forming a first semiconductor layer, a second semiconductor layer, a third semiconductor layer, and a fourth semiconductor layer over the substrate;
• removing portions of the second semiconductor layer, the third semiconductor layer and the fourth semiconductor layer to form a plurality of mesas separated from each other by a plurality of trenches over the substrate;
• performing a lateral etching to remove a portion of the third semiconductor layer to form an island between the second semiconductor layer and the fourth semiconductor layer within each mesa;
• and
• performing an epitaxial growth operation to seal the trench with a semiconductor material and form a first void extending along a first direction and a second void extending along a second direction different from the first direction.