Abstract:
A packaged semiconductor device (450) includes a semiconductor chip (400) having at least one selectively thinned substrate (cavity) region (410). A package (460) is provided for mounting, enclosing and electrically connecting the chip (400) to the outside world, and structure for applying external stress (470) to induce strain in the thinned substrate region (410). The external stress is preferably adjustable, such as by varying the gas flow (or a vacuum) applied through a pressure valve.