Simplified carrier removable by reduced number of CMP processes

A method comprising:

• forming a composite carrier comprising:
• depositing an oxide-based layer over a silicon base carrier;
• depositing a first nitride-based layer over the oxide-based layer;
• depositing a second nitride-based layer over the first nitride-based layer;
• and
• depositing a third nitride-based layer over the second nitride-based layer, wherein a first material of the first nitride-based layer is different from a second material of the second nitride-based layer and a third material of the third nitride-based layer;
• bonding a package component over the third nitride-based layer;
• performing a first polishing process to remove the silicon base carrier;
• performing a second polishing process to remove the oxide-based layer;
• and
• performing a third polishing process to remove the first nitride-based layer, the second nitride-based layer, and the third nitride-based layer, wherein the third polishing process is stopped on the package component.

A method comprising:

• forming a composite carrier comprising:
• a base carrier;
• a silicon oxide layer over and contacting the base carrier;
• a silicon nitride layer over and contacting the silicon oxide layer;
• a first silicon oxynitride layer over and contacting the silicon nitride layer;
• and
• a second silicon oxynitride layer over and contacting the first silicon oxynitride layer;
• and
• joining a package component over and bonding to the composite carrier, wherein the package component comprises:
• a second silicon oxide layer bonding to the second silicon oxynitride layer.