Thin film formation method, and functional material and applied device there with background of the invention

Abstract

In a laser ablation method comprising the steps of irradiating a laser beam to target material 107, and depositing ejected species from the target material on a faced substrate 109 to form a thin film, an ambient gas is introduced into reaction chamber 101 under a constant certain pressure when the laser ablation is performed, using a target material with almost or the same composition as that of a thin film to be obtained. It is thereby possible to obtain a thin film with the same composition as that of the target material readily, without requiring an introduction of O 2 g as and a substrate heating. As a result, it is not necessary to limit materials for a substrate, and it is possible to adjust the adaptability of an anaerobic process.

What is claimed is:  
     
         1 . An optoelectronic material comprising: 
 a transparent conducting film produced by placing a target material and a substrate in a reaction chamber; adjusting a pressure (P) of an ambient gas to be introduced to the reaction chamber and a distance (D) between the substrate and the target material so that crystal nucleus growth in a vapor phase is carried out in an area generated by a shock front in which oxidization is promoted; exciting the target material by irradiating a laser beam to the target material, while introducing the ambient gas into the reaction chamber under the pressure; and forming a thin film by depositing species, which are contained in said target material and ejected from said target material by being irradiated by the laser beam, on said substrate; and    ultrafine particles of light-emitting semiconductor dispersed in said transparent conducting film.    
     
     
         2 . An optoelectronic material obtainable by: 
 placing a substrate and a target material including at least two kinds of areas with different compositions in a target material in a reaction chamber;    adjusting a pressure (P) of an ambient gas and a distance (D) between said substrate and said target material so that crystal nucleus growth in a vapor phase is carried out in an area generated by a shock front in which oxidization is promoted;    exciting said target material by irradiating a laser beam to said target material, while introducing said ambient gas into said reaction chamber under said pressure; and    forming a thin film by depositing species, which are contained in said target material and ejected from said target material by being irradiated by the laser beam, on said substrate.    
     
     
         3 . A ferroelectric memory device using a ferroelectric film produced by placing a target material and a substrate in a reaction chamber; adjusting a pressure (P) of an ambient gas to be introduced to the reaction chamber and a distance (D) between the substrate and the target material so that crystal nucleus growth in a vapor phase is carried out in an area generated by a shock front in which oxidization is promoted; exciting the target material by irradiating a laser beam to the target material, while introducing the ambient gas into the reaction chamber under the pressure; and forming a thin film by depositing species, which are contained in the target material and ejected from the target material by being irradiated by the laser beam, on the substrate.  
     
     
         4 . The device according to  claim 3 , including CMOS as a drive circuit.  
     
     
         5 . An IC card provided with a ferroelectric memory device according claim  3 .