Light-irradiation heat treatment method and heat treatment apparatus

A heat treatment method of irradiating a substrate with a flash of light to heat said substrate, comprising steps of:

• (a) carrying a first substrate before treatment into a first cool chamber and supplying a nitrogen gas to said first cool chamber to replace an atmosphere to a nitrogen atmosphere;
• (b) taking said first substrate out from said first cool chamber and carrying said first substrate into a treatment chamber connected to a transport chamber using a transport robot which is provided in said transport chamber connected to said first cool chamber;
• (c) irradiating said first substrate in said treatment chamber with a flash of light to heat said first substrate;
• (d) carrying said first substrate after heat treatment out of said treatment chamber and delivering said first substrate to said first cool chamber using said transport robot;
• (e) cooling said first substrate in said first cool chamber and carrying said first substrate after being cooled out of said first cool chamber;
• (f) carrying a second substrate before treatment into a second cool chamber connected to said transport chamber and supplying a nitrogen gas to said second cool chamber to replace an atmosphere with a nitrogen atmosphere;
• (g) taking said second substrate out from said second cool chamber and carrying said second substrate into said treatment chamber using said transport robot;
• (h) irradiating said second substrate in said treatment chamber with a flash of light to heat said second substrate;
• (i) carrying said second substrate after heat treatment out of said treatment chamber and delivering said second substrate to said second cool chamber using said transport robot;
• and
• (j) cooling said second substrate in said second cool chamber and carrying said second substrate after being cooled out of said second cool chamber, wherein
• steps from said step (a) to said step (e) and steps from said step (f) to said step (j) are alternately repeated.