激光诱导扩散区温度分布的均匀化

用连续波激光诱导扩散制作单片集成光接收机中的探测器时，激光照射形成的高温区面积很小。当入射激光焦斑光强为高斯分布甚至“平顶帽形”分布时，微小扩散区温度分布的均匀性都不能达到实验的要求。提出了用掩模对入射高斯光束进行空间调制的方法来实现扩散区温度的均匀化。该方法的关键是计算出实现均匀的温度分布所需要的焦斑光强分布参数。给出了计算方法和计算实例。结果表明，均匀化后，在扩散区平均温度上升值为500K时，扩散区内的最大温度差为3．9K，并且高温区的温度分布接近“平顶帽形”。

Flatting of Temperature Distribution in Laser Induced Diffusion Region

In the fabrication of photodiode of monolithic integrated photoreceiver using laser induced diffusion, because the high temperature region is very small, when the intensity distribution of incident laser beam is Gaussian or uniform, the uniformity of the temperature distribution in the diffusion region cannot meet the requirement of uniformity. In this paper, a method to homogenize the temperature through modulating of the intensity incident on the surface using a mask is proposed. The key of this method is calculating the laser intensity distribution, which can induce uniform temperature rise in the diffusion region. The numerical method to solve this problem is described. The results show that when the mean temperature rise in the diffusion region is about 500 K, the maximum temperature difference of 3.9 K can be achieved, and the temperature distribution approaches “flatcap”.