摘要：以氟化氢为基础的溶液被广泛地用在扩散前清洗工艺中的二氧化硅清洗与蚀刻中。为降低不同批次之间工艺效果的差别，也就是增加批次与批次之间工艺效果的可重复性，更好地控制氧化物地腐蚀显得尤为重要。自动化的蚀刻控制体系弥补了在线的化学品浓度与反应温度的偏差而达到了精确的蚀刻目标。
关键词：可重复性；清洗；腐蚀
1 introduction spray processors are dry-in/dry-out wet cleaning systems capable of being used at virtually all wet cleaning steps for both feol and beol applications. batch spray processors are typically configured with up to eight chemical inputs, in addition to di water, and up to two recirculation systems. chemicals can be dispensed individually or mixed with each other and/or di water. once mixed the chemicals are dispensed onto the wafers in a process chamber, as shown in figure 1. this mixing flexibility is used to generate a wide range of chemical mixtures that can be dispensed at ambient temperature or heated with an infrared chemical heater. spray processors have a number of advantages.they typically have a smaller footprint since all processing is performed in a single chamber. all chemical that is dispensed onto a wafer surface is either fresh or freshly filtered. since the wafers are rotated during the cleaning process, centrifugal force enhances particle removal efficiency and overall rinse efficiency. enhanced rinse efficiency lowers overall di water consumables when compared to comparable immersion processes. while recirculation is available, for many applications it is not neededdue to the highly efficient chemical usage and low cost of consumption. the single-pass processing, made affordable by spray process, eliminates the risk of cross-contamination. 2 oxide etching due to fluctuation in incoming di water temperature, exothermic reaction of di and hf mixing and different tool idle time, there can be significant temperature difference during etch process and among different batches. figure 2 shows the actual process temperature from different runs. a temperature difference of 2℃ was observed, and it caused a large etch rate difference, as shown in figure 3. although the average etch rate was close to the target, the run-to-run etch rate repeatability deviation was about 6.5%, which was too large for requirements of the pre-diffusion clean process. in order to reduce the etch rate variation and improve run-to-run repeatability, etch time should be controlled to compensate for temperature and concentration variation. automated etch control was developed based on these concepts and is described in the following paragraphs. 3 automated etch control the etch control option automatically controls the length of etch steps by measuring and adjusting for concentration of the etchant and wafer temperature. the etch control process is defined by a base etch rate which assumes a constant temperature (base temperature) and a constant chemicalconcentration (base concentration). because variations in temperature and concentration affect the etch rate, etch control sof
赵水林，葛晓景 | （上海先进半导体制造有限公司，fsi international 上海 200233） |
摘要：以氟化氢为基础的溶液被广泛地用在扩散前清洗工艺中的二氧化硅清洗与蚀刻中。为降低不同批次之间工艺效果的差别，也就是增加批次与批次之间工艺效果的可重复性，更好地控制氧化物地腐蚀显得尤为重要。自动化的蚀刻控制体系弥补了在线的化学品浓度与反应温度的偏差而达到了精确的蚀刻目标。
关键词：可重复性；清洗；腐蚀
1 introduction spray processors are dry-in/dry-out wet cleaning systems capable of being used at virtually all wet cleaning steps for both feol and beol applications. batch spray processors are typically configured with up to eight chemical inputs, in addition to di water, and up to two recirculation systems. chemicals can be dispensed individually or mixed with each other and/or di water. once mixed the chemicals are dispensed onto the wafers in a process chamber, as shown in figure 1. this mixing flexibility is used to generate a wide range of chemical mixtures that can be dispensed at ambient temperature or heated with an infrared chemical heater. spray processors have a number of advantages.they typically have a smaller footprint since all processing is performed in a single chamber. all chemical that is dispensed onto a wafer surface is either fresh or freshly filtered. since the wafers are rotated during the cleaning process, centrifugal force enhances particle removal efficiency and overall rinse efficiency. enhanced rinse efficiency lowers overall di water consumables when compared to comparable immersion processes. while recirculation is available, for many applications it is not neededdue to the highly efficient chemical usage and low cost of consumption. the single-pass processing, made affordable by spray process, eliminates the risk of cross-contamination. 2 oxide etching due to fluctuation in incoming di water temperature, exothermic reaction of di and hf mixing and different tool idle time, there can be significant temperature difference during etch process and among different batches. figure 2 shows the actual process temperature from different runs. a temperature difference of 2℃ was observed, and it caused a large etch rate difference, as shown in figure 3. although the average etch rate was close to the target, the run-to-run etch rate repeatability deviation was about 6.5%, which was too large for requirements of the pre-diffusion clean process. in order to reduce the etch rate variation and improve run-to-run repeatability, etch time should be controlled to compensate for temperature and concentration variation. automated etch control was developed based on these concepts and is described in the following paragraphs. 3 automated etch control the etch control option automatically controls the length of etch steps by measuring and adjusting for concentration of the etchant and wafer temperature. the etch control process is defined by a base etch rate which assumes a constant temperature (base temperature) and a constant chemicalconcentration (base concentration). because variations in temperature and concentration affect the etch rate, etch control sof
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