Atmospheric pressure cold plasma has the advantages of high reactive species content, free from the limitation of vacuum environment and low cost in polymer films pattern etching. However, due to the extension phenomenon of the jet, there are problems in the pattern etching, such as low processing accuracy and difficulty in process precise control. In this paper, an atmospheric pressure cold plasma jet diffusion limited etching model is established to simulate the etching process and surface etching morphology under different conditions, and a plasma jet processing platform is built for experimental confirmation. The effect of diffusion coefficient and move probability on the etching results is studied by numerical simulation. The experiment observes the extension phenomenon of the plasma jet hitting the glass slide under the influence of working voltage or nitrogen flow, and the color reaction of Starch-KI test paper. The results show that the simulated etching results are consistent with the extension phenomenon of the jet impinging on the glass slide. The greater the probability of the active particles moving downward, the greater the contact line width and the etching depth, which is the same as the experimental result of increasing the working voltage. The shielding gas can isolate the air, reduce the diffusion coefficient, and reduce the loss of particles, which is beneficial to plasma etching. It is hoped that the research results in this paper can provide a certain reference for realizing high-precision and controllable etching and process optimization of atmospheric pressure cold plasma jet.

常压冷等离子体在聚合物薄膜图形蚀刻中具有反应物种含量高、不受真空环境限制、成本低等优点。然而，由于射流的延伸现象，图案蚀刻存在加工精度低、工艺精确控制困难等问题。本文建立了常压冷等离子体射流扩散受限蚀刻模型，模拟了不同条件下的蚀刻过程和表面蚀刻形貌，并搭建了等离子体射流加工平台进行实验验证。通过数值模拟研究了扩散系数和移动概率对刻蚀结果的影响。实验观察了等离子射流在工作电压或氮气流影响下撞击载玻片的延伸现象，以及Starch-KI试纸的显色反应。结果表明，模拟蚀刻结果与射流撞击载玻片的延伸现象一致。活性粒子向下移动的概率越大，接触线宽度和蚀刻深度越大，这与提高工作电压的实验结果相同。保护气体可以隔绝空气，降低扩散系数，减少颗粒的损失，有利于等离子刻蚀。