Patent ID: 6926801

Claim:
A laser machining apparatus for removing a desired portion on a substrate by irradiating said substrate with a laser beam in an atmosphere of a source gas, comprising: a laser irradiation and observation system for performing optical observation on a portion to be machined on said substrate held on a X-Y positioning stage and irradiation with said laser beam, a gas enclosure for forming a local atmosphere of an etching source gas or a local atmosphere of a CVD source gas around said portion to be machined with a small gap formed between a surface to be machined and said gas enclosure without contact with said surface to be machined on said substrate, and a source gas feeding and exhausting unit for feeding said source gas into said gas enclosure and exhausting it from said gas enclosure, wherein: said substrate has said surface to be machined directed downward, said laser irradiation and observation optical system is arranged to perform said optical observation and said irradiation with said laser beam on a desired portion on said substrate from below, and said gas enclosure comprises a nozzle for blowing said source gas on a laser beam irradiation position of the portion to be machined on said substrate; a inlet port shaped like a crescent moon having the center of its opening positioned symmetrically with said nozzle with respect to said laser irradiation portion which is positioned in between said nozzle and said center in a horizontal plane; and a purge gas blowoff port shaped like a donut having opening widths varied such that the amount of purge gas blowing off from the opening portion near said inlet port is more than the amount of purge gas blowing off from the opening portion near said nozzle.