PROBLEM TO BE SOLVED: To easily and securely conduct a treatment of a compound semiconductor that is extremely susceptible to a thermal process and related processes by allowing a compound containing a prescribed impurity of a conductive type to adhere to the surface of a detector and irradiating the compound with laser beam in a high-pressure atmosphere of an inactive gas.
SOLUTION: A wafer of CdTe, for example, is put under a vacuum in an evaporation container 20 and Na2Te, for example, is evaporated onto the wafer. Then, it is placed on a substrate holder 16 in a laser irradiation chamber 15 and nitrogen or argon gas of about 5 to 10 atmospheric pressure is introduced. In this process, the evaporated surface of the wafer is not exposed to air or an atmosphere containing water. Subsequently, laser 10 is actuated and laser beam 12 is radiated onto the wafer in the form of a pattern. After the wafer is transferred to the vacuum evaporation container 20 and metal used for electrodes is evaporated onto the wafer, it is transferred to the irradiation chamber 15 again and is irradiated with ultraviolet laser under a high vacuum to isolate the elements. An isolation groove is formed in this way, and elements are made in such a series of processes.