The present invention relates to a manufacturing method for a semiconductor device and a manufacturing apparatus for a semiconductor device, for example, used for activation anneal of a semiconductor wafer.
To improve a current driving force of a transistor with the recent tendency of high integration and high performance of a semiconductor device, spike RTA (Rapid Thermal Annealing) is used in an anneal process for forming a source-drain diffusion layer. According to the spike RTA, a wafer is irradiated with the light of high energy using, for example, a halogen lamp as a heat source to rapidly raise or lower the temperature of the wafer to reach approximately 1,000° C. Hence, impurities can be prevented from diffusing in a depth direction to ensure ion activation.
On the other hand, a wafer in-plane radiation factor of a wafer heated by the spike RTA may significantly vary due to, for example, formation of a pattern having a different multi layered film structure or shape on the wafer. In a region having a low radiation factor, a sufficient amount of light energy cannot be absorbed while a wafer is being annealed. For example, even when a wafer needs to reach a temperature of 1,000° C. for activation, a temperature may reach no more than approximately 900° C. and hence cannot reach a required temperature for activation of impurities. As a result, impurities are not sufficiently activated and a resistance difference is generated within the wafer surface, thus causing a disadvantage such as degradation in transistor performance.
Japanese Patent Application Laid-Open No. 2007-95889 (e.g., claim 1, paragraph [00421]), for example, discloses a method for heating an object to be treated having variable radiation factor distribution to obtain a uniform distribution. However, a control system for controlling a heating temperature in a wafer surface becomes complicated, which causes a disadvantage of difficulty in close temperature control.
USPTO Backgrounds
USPTO Backgrounds