湿法刻蚀车间有害气体扩散规律及控制技术数值模拟

Numerical simulation for the harmful gas diffusion in the wet-etching workshop of IC manufacturing factories

集成电路制造企业湿法刻蚀工序中使用了大量的刻蚀液,且刻蚀液极易挥发。为有效防治集成电路制造业湿法刻蚀车间有害气体的扩散,保护作业人员的身体健康,采用CFD方法对刻蚀车间更换刻蚀液的过程进行数值模拟计算,研究有害气体扩散的规律和控制技术。结果表明:刻蚀设备局部通风的风速和车间局部排风罩的位置是影响有害气体质量浓度分布的关键因素。当刻蚀设备的局部排风风速为6m/s,并在刻蚀设备上方车间顶部设置局部排风罩时,可使车间内作业工位处HF的质量浓度降到职业接触限值(2 mg/m^3)以下。

This paper is aimed at controlling and preventing the diffusion of harmful gas in the wet-etching workshop of IC manufacturing factories effectively in hoping to protect the health of the operator.As a matter of fact,the adoption of large amounts of etching solution in the wet etching process of the integrated circuit(IC)manufacture may inevitably bring about highly harmful volatile toxins.To simulate the process of replace the etching solution and control the harmful gas in the wet etching workshop with other effective means,we have managed to make a numerical simulation by using the so-called CFD software.Furthermore,we have also made an investigation and study of the distribution features and diffusion regulations of the harmful gas,including the flowing field of such gas and the content concentration distribution over there,in addition to the effect of the local ventilation on the diffusion of the aforementioned harmful gas.As a result of the above said investigation of the local ventilation,we have made it out that:(1)The HF concentration distribution in the wet etching workshop and HF concentration distribution with the time at the 1^st,2^nd,3^rd monitoring sites under the different airflow velocities of local exhaust and different local exhaust volumes;(2)The HF concentration distribution in the wet etching workshop and HF concentration distribution changing with the time at the 1^st,2^nd and the 3^rd monitoring sites under the different local exhaust vents;(3)The HF concentration distribution in the wet etching workshop and the HF concentration distribution changing with the time at the 1^st,and the 2^nd and 3^rd monitoring sites by increasing the local ventilations in the workshop.Thus,the final results demonstrate that the local ventilation speed of the etching equipment and the position of the local exhaust hood of the workshop serve as the principal factors affecting the distribution of the harmful gas.Therefore,the paper takes the increase of the wind speed of the local ventilation in the etching equipment,and the local exhaust ventilation of setting up the door of the etching equipment on the ceiling as the optimalized condition.And,finally,when the wind speed of the local ventilation in the etching equipment keeps at 6 m/s and the local exhaust vent can be set up to the workshop ceiling by the door of the etching device,it has been made possible to reduce the concentration of HF in the etching workshop below the OEL(2 mg/m^3).