Process for hardening active electronic components against ionizing radiations, and hardened components of large dimensions

Process for hardening substrates for active electronic components of large dimensions against ionizing radiations, characterized in that their basic structure is produced by forming on a surface of a substrate of monocrystalline silicon having at least one dimension in excess of 50 mm (1) a layer (2) of "hardening" material of polycrystalline stabilized zirconia exhibiting a product .mu...delta. of less than approximately 5.10.sup.-8 cm.sup.2.V.sup.1, .mu. being the mobility, expressed in cm.sup.2.V.sup.1 s.sup.-1, of the carriers photogenerated under ionizing radiation, and .delta. their lifetime expressed in seconds, and in that a layer of monocrystalline silicon (3) is formed on this layer of "hardening" material.