Generally, the present invention utilizes a lower electrode comprising a sidewall spacer to form a top surface with rounded corners on which HDC material can be deposited without substantial cracking. An important aspect of the present invention is that the sidewall spacer does not reduce the electrical contact surface area between the lower electrode and the HDC material layer as compared to a similar structure containing a lower electrode without a sidewall spacer. One embodiment of the present invention is a microelectronic structure comprising a supporting layer (e.g. Si substrate 30) having a principal surface, a lower electrode overlying the principal surface of the supporting layer, and a high-dielectric-constant material layer (e.g. BST 44) overlying the top surface of the lower electrode. The lower electrode comprises an adhesion layer (e.g TiN 36), an unreactive layer (e.g. Pt 42), a sidewall spacer (e.g. SiO.sub.2 40) and a top surface, with the sidewall spacer causing the top surface to have a rounded corner. The rounded corner of the top surface minimizes crack formation in the high-dielectric-constant material layer.