以重掺杂自截止腐蚀工艺制备的厚度为 3～ 4μm的自支撑Si平面薄膜已在X光激光和惯性约束聚变分解实验中得到应用。制备过程中 ,重掺杂B杂质的引入会对获得的Si平面薄膜的应用带来影响。本工作研究采用次级离子质谱 (SIMS)测量Si平面薄膜中B杂质的浓度分布 ,结合在软X光波段下同步辐射直接测得的Si薄膜的透过率结果 ,分析B等杂质对Si平面薄膜性能的影响 Self-supporting Si planar films with a thickness of 3 ~ 4μm prepared by heavily doped etch-off etching have been used in X-ray laser and inertial confinement fusion decomposition experiments. During the preparation process, the introduction of heavily doped B impurities will affect the application of the obtained Si planar film. In this work, we used secondary ion mass spectrometry (SIMS) to measure the concentration distribution of B impurity in Si planar films. Combined with the transmittance of Si films directly measured by synchrotron radiation in the soft X-ray waveband, Effect of film properties