Computational data: Role of idealized surface representations in computational AS-ALD: Assessing trimethoxypropylsilane blocking performance for Al₂O₃ deposition with crystalline SiO₂

Area-selective atomic layer deposition (AS-ALD) using small molecule inhibitors (SMIs) holds promise for thin-film patterning but suffers from selectivity loss over multiple cycles. This study explores the mechanisms causing this loss during Al2O3 growth with SiO2 as the non-growth surface, inhibited by trimethoxypropylsilane (TMPS). We analyze SMI adsorption, maximum coverage, precursor penetration, and reactions with surface hydroxyl groups. Using a crystalline α-quartz slab to model SiO2, we compare outcomes to previous amorphous surface studies to evaluate the validity of idealized models. We find that TMPS achieves inhibitor densities similar to those in amorphous models but does not fully saturate surface hydroxyls. Precursor access through the inhibitor layer depends on molecular size, adsorption energetics, and dimerization. Larger species like TDMAA and DMAI are effectively blocked, while smaller ones such as TMA and AlCl3 reach exposed OH groups, leading to ALD reactions at these sites and selectivity loss. Although findings generally align with those from amorphous surface models, distinctions emerge: amorphous models better reflect realistic OH densities and bonding diversity, capturing surface chemistry more accurately. Thus, while idealized (crystalline) models inform general SMI behavior, amorphous models are crucial for a more comprehensive understanding of AS-ALD selectivity and inhibitor mechanisms. Both approaches should be integrated for future studies.区域选择性原子层沉积（Area-selective atomic layer deposition, AS-ALD）借助小分子抑制剂（small molecule inhibitors, SMIs）实现薄膜图案化，具备可观应用潜力，但该技术在多循环工艺中易出现选择性损失问题。本研究针对以二氧化硅（SiO₂）为非生长表面、三甲氧基丙基硅烷（trimethoxypropylsilane, TMPS）为抑制剂的三氧化二铝（Al₂O₃）生长体系，探究了引发选择性损失的内在机制。我们对小分子抑制剂的吸附行为、最大覆盖度、前驱体渗透过程以及与表面羟基的反应进行了系统分析。本研究采用结晶α-石英平板模拟二氧化硅表面，并将所得结果与此前的非晶表面研究进行对比，以评估理想化模型的有效性。研究发现，三甲氧基丙基硅烷（TMPS）可达到与非晶模型中相近的抑制剂覆盖密度，但无法完全饱和表面羟基位点。前驱体能否穿透抑制剂层，取决于分子尺寸、吸附能以及二聚化过程。诸如TDMAA、DMAI等较大分子会被有效阻挡，而TMA、AlCl₃这类较小分子则可抵达暴露的羟基位点，进而在这些位点发生原子层沉积反应，引发选择性损失。尽管本研究结果与非晶表面研究的结论大体一致，但仍存在显著差异：非晶模型能够更好地反映真实的羟基密度与成键多样性，更精准地刻画表面化学过程。因此，尽管理想化（结晶型）模型可用于揭示小分子抑制剂的一般行为规律，但非晶模型对于更全面地理解区域选择性原子层沉积的选择性机制与抑制剂作用机理至关重要。未来的相关研究应将这两种研究方法相结合。