Heat treatment method and heat treatment apparatus for heating substrate by irradiating substrate with light

Abstract

A surface of a semiconductor wafer with a gate of a high dielectric constant film formed thereon is heated to a target temperature for a short time by irradiating the surface with a flash of light. This promotes the crystallization of the high dielectric constant film while suppressing the growth of an underlying silicon dioxide film. Subsequently, the temperature of the semiconductor wafer subjected to the flash heating is maintained at an annealing temperature by irradiating the semiconductor wafer with light from halogen lamps. An annealing process after the flash heating is performed in an atmosphere of a gas mixture of hydrogen gas and nitrogen gas. The annealing process is performed on the semiconductor wafer in the atmosphere of the hydrogen-nitrogen gas mixture, so that defects present near the interfaces of the high dielectric constant film are eliminated by hydrogen termination.

What is claimed is: 
     
         1 . A heat treatment apparatus for irradiating a substrate with a high dielectric constant film formed thereon with light to heat the substrate, thereby promoting the crystallization of said high dielectric constant film, said heat treatment apparatus comprising:
 a chamber for receiving therein the substrate with said high dielectric constant film formed thereon;   a holder for holding said substrate in said chamber;   a flash lamp for irradiating a surface of said substrate held by said holder with a flash of light to heat the surface of said substrate including said high dielectric constant film to a first temperature;   a halogen lamp for irradiating said substrate held by said holder with light;   an atmosphere forming part for supplying any gas selected from the group consisting of hydrogen, ammonia, hydrogen chloride, sulfur dioxide, nitrous oxide, and hydrogen sulfide into said chamber to form an atmosphere containing said gas within said chamber; and   a controller for controlling the emission of light from said halogen lamp and said atmosphere forming part so as to irradiate said substrate with light from said halogen light, thereby maintaining the temperature of said substrate at a second temperature lower than said first temperature, while forming an atmosphere containing said gas within said chamber.   
     
     
         2 . The heat treatment apparatus according to  claim 1 , wherein
 said second temperature is in the range of 300° to 700° C., and   said controller controls the emission of light from said halogen lamp so as to maintain the temperature of said substrate at said second temperature for a time period in the range of two seconds to 30 minutes.   
     
     
         3 . The heat treatment apparatus according to  claim 1 , wherein
 said controller controls the emission of light from said halogen lamp so as to maintain the temperature of said substrate at said second temperature after the surface of said substrate is heated to said first temperature by the irradiation with a flash of light from said flash lamp.   
     
     
         4 . The heat treatment apparatus according to  claim 3 , wherein
 said controller controls the emission of light from said halogen lamp so as to heat said substrate to said second temperature before the surface of said substrate is heated to said first temperature by the irradiation with a flash of light from said flash lamp.   
     
     
         5 . The heat treatment apparatus according to  claim 1 , wherein
 a gate electrode including at least one metal selected from the group consisting of titanium, zirconium, hafnium, vanadium, niobium, tantalum, molybdenum, and tungsten is formed on said high dielectric constant film.   
     
     
         6 . The heat treatment apparatus according to  claim 1 , wherein
 said high dielectric constant film includes at least one selected from the group consisting of TiN, ZrN, HfN, VN, NbN, TaN, MoN, WN, TiSiN, HfSiN, VSiN, NbSiN, TaSiN, MoSiN, WSiN, HfAlN, VAlN, NbAlN, TaAlN, MoAlN, and WAlN.