PURPOSE: To realize integration of a piezoelectric body device and a semiconductor circuit, and to facilitate miniaturization of an electronic circuit utilizing the piezoelectric device by cleaning a flat surface of a piezoelectric body and a semiconductor, and thereafter, superposing them and bringing them into contact with each other, and joining them directly by applying a voltage to the contact boundary.
CONSTITUTION: The surfaces to be joined, of a piezoelectric body substrate 11 and a semiconductor substrate 12 are subjected to mirror grinding flatly, and washed, and organic dirt, an oil film or a minute stuck object, etc., are eliminated. Thereafter, the piezoelectric body substrate 11 and the semiconductor substrate 12 are superposed and each joined surface is brought into contact with each other, fixed to a jig for applying a voltage and put into a vacuum tank. Subsequently, the vacuum tank is evacuated, and by applying a DC voltage to the boundary brought into contact, a piezoelectric composite substrate on which the piezoelectric body substrate 11 and the semiconductor substrate 12 are joined directly is obtained. In such a way, the piezoelectric body 11 and the semiconductor 12 can be joined directly, respectively, the piezoelectric body 11 and the semiconductor 12 do not spoil its crystalline property, respectively, and a resonance characteristic, a temperature characteristic, etc., in the case the piezoelectric body which can be formed on the semiconductor substrate is a piezoelectric device such as a resonator, etc., are not deteriorated either.
TOMITA YOSHIHIRO
EDA KAZUO
