The present disclosure describes forming a crystalline high-k dielectric layer at a reduced crystallization temperature in a semiconductor device. The method includes forming a channel structure on a substrate, forming an interfacial layer on the channel structure, forming a first high-k dielectric layer on the interfacial layer, forming dipoles in the first high-k dielectric layer with a dopant, and forming a second high-k dielectric layer on the first high-k dielectric layer. The dopant includes a first metal element. The second high-k dielectric layer includes a second metal element different from the first metal element.