A low-temperature sintering dielectric composition contains barium titanate (BaTiO.sub.3) as a main ingredient and accessory ingredients including 1.0 to 2.0 mol % of barium carbonate (BaCO.sub.3), 0.5 to 1.0 mol % of at least one rare earth oxide selected from the group consisting of Y.sub.2O.sub.3, Ho.sub.2O.sub.3, Dy.sub.2O.sub.3, and Yb.sub.2O.sub.3, 0.1 to 1.0 mol % of manganese oxide (MnO), and 1.0 to 2.0 mol % of borosilicate based glass, based on 100 mol % of the main ingredient.

A handle substrate of a composite substrate for a semiconductor is provided. The handle substrate is composed of polycrystalline alumina. The handle substrate includes an outer peripheral edge part with an average grain size of 20 to 55 m and a central part with an average grain size of 10 to 50 m. The average grain size of the outer peripheral edge part is 1.1 times or more and 3.0 times or less of that of the central part of the handle substrate.

A toughened ceramic component having a residual compressive stress and methods of forming the toughened ceramic component is disclosed. The ceramic component may include an internal portion having a first coefficient of thermal expansion (CTE) and an external portion substantially surrounding the internal portion and forming an exterior surface of the ceramic component. The external portion may have a second CTE that is less than the first CTE. Additionally, the external portion may be in compressive stress.