Abstract: In a general aspect, a ceramic thin film with nanotwinned regions at a tunable volume fraction is manufactured. In some aspects, a method for manufacturing a ceramic thin film on a surface of a substrate in an evacuated chamber is disclosed. The ceramic thin film includes crystalline grains; and each of the crystalline grains includes one or more nanotwinned regions. The one or more nanotwinned regions have a volume fraction in a range of 30-80% of the ceramic thin film. The ceramic thin film comprises titanium, nitrogen, and boron. A plurality of targets including a plurality of sputtering materials is prepared. A gas atmosphere in the evacuated chamber is formed. Electric power is supplied to the plurality of targets to cause co-sputtering of the plurality of sputtering materials to form the ceramic thin film with the one or more nanotwinned regions.