In Vacuo Photoemission Studies of Platinum Atomic Layer Deposition Using Synchrotron Radiation

Abstract

The mechanism of platinum atomic layer deposition using (methylcyclopentadienyl)trimethylplatinum and oxygen is investigated with in vacuo photoemission spectroscopy at the Stanford Synchrotron Radiation Lightsource. With this surface-sensitive technique, the surface species following the Pt precursor half cycle and the oxygen counter-reactant half cycle can be directly measured. We observed significant amounts of carbonaceous species following the Pt precursor pulse, consistent with dehydrogenation of the precursor ligands. Significantly more carbon is observed when deposition is carried out in the thermal decomposition temperature region. The carbonaceous layer is removed during the oxygen counter reactant pulse, and the photoemission spectrum shows that a layer of adsorbed oxygen remains on the surface as previously predicted.

In situ synchrotron based x-ray techniques as monitoring tools for atomic layer deposition

“…There are however several examples of the use of XPS as in vacuo technique, meaning that the sample gets transferred from an ALD chamber to an XPS analysis chamber under UHV conditions. 37,38,[42][43][44][45] However, the development of high pressure XPS and ambient pressure XPS systems, as are currently pioneered for in situ studies during catalysis, could make in situ XPS possible under ALD conditions. 73 …”

(Invited) Catalytic Surface Reactions during Nucleation and Growth of Atomic Layer Deposition of Noble Metals: A Case Study for Platinum

“…Further experimental evidence for the occurrence of dehydrogenation reactions during Pt ALD was recently reported by Geyer et al (18). The formation of a carbonaceous layer during the MeCpPtMe 3 pulse was observed by synchrotron-based photoemission spectroscopy (18).…”

“…The formation of a carbonaceous layer during the MeCpPtMe 3 pulse was observed by synchrotron-based photoemission spectroscopy (18). Furthermore, for Ru ALD from CpRu(CO) 2 Et and O 2 gas, H 2 was detected as a major reaction product during the precursor pulse (36), indicating the occurrence of dehydrogenation reactions also for Ru ALD.…”

“…Several studies in the past decade were devoted to obtaining a deeper understanding of the reaction mechanisms of noble metal ALD processes (13)(14)(15)(16)(17)(18). Initially, the reaction mechanisms were mainly studied by identifying the reaction products formed during the process.…”

Recent advances in mechanism investigation of atomic layer deposition by <italic>in situ</italic> photoelectron spectroscopy

“…单腔 室型如图2(a)所示, 向PES分析室内直接通入ALD前驱 体, 进行ALD沉积并直接测试分析样品表面 [51] . 但由 于PES分析室通常要求超高真空度 [55] (网络版彩图) 图 5 (a) 配体裂解反应机制图; (b) 使用MeCpPtMe 3 和氧气 ALD沉积Pt过程中的PES谱 [58] (网络版彩图) 程中, Bayer等 [38] 通过原位XPS研究发现ITO中的氧离 子会不断扩散到表面与三甲基铝反应, 从而导致表面 反应不再满足自限性. 界面处的元素扩散过程总体上 受温度影响 [69] , 同时也可能受到前驱体吸附或沉积过 程中产生的化学势梯度的影响 [31] .…”