摘要 |
A semiconductor device is formed by forming a second trench 120 at the base of a first trench 18, depositing insulator 124 at the base of the second trench 120, and then etching cavities 26 laterally from the sidewalls of the second trench, but not the base which is protected by insulator 124. The invention may in particular be used to form semiconductor devices with cavities under the active components, or by filling the cavities to form silicon on insulator or silicon on conductor devices.
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