A semiconductor device includes a substrate having at least one trench with corrugated sidewall surface. At least one trench capacitor is located in the at least one trench. The at least one trench capacitor includes inner and outer electrodes with a node dielectric layer therebetween. At least one transistor is provided on the substrate. The at least one transistor comprises a source region and a drain region, a channel region between the source region and the drain region, and a gate over the channel region. The source region is electrically connected to the inner electrode of the at least one trench capacitor.