| abstract |
This compound substrate for use with a semiconductor comprises a handle substrate (11) and a donor substrate joined to the surface of said handle substrate (11) either directly or with a joining layer interposed therebetween. The handle substrate (11) is formed from an insulating polycrystalline material. The surface (15) of the handle substrate (11) has a microscopic center-line average roughness (Ra) of at most 5 nm, and concavities (6) are formed in said surface. |