High surface passivation quality and thermal stability of ALD Al2O3 on wet chemical grown ultra-thin SiO2 on silicon

Impact of thin intermediate thermal oxide films on the properties of PECVD passivation layer systems

“…Another approach is the use of a thermally grown silicon oxide layer or a combination of a thin thermal oxide film with a dielectric capping layer [9][10][11][12][13][14]. The literature provides some investigations of stack systems consisting of thermally or wet chemically grown or deposited oxide layers with different capping layers [8,[14][15][16]. So far, the role of the oxide layer thickness was not investigated in detail.…”

Uniformity and passivation research of Al2O3 film on silicon substrate prepared by plasma-enhanced atom layer deposition

“…Samples were cleaned in sulphuric acid mixture with hydrogen peroxide at 110°C for 10 min to oxidate and remove organic impurities on surface and also to dissolve metal ions from surface to solution. Then, samples were treated in hydrofluoric acid for 1 min at room temperature to remove silicon oxide which is 2 to 4 nm [4]. At last, samples were capped with PEALD Al 2 O 3 using Al(CH 3 ) 3 (TMA) and plasma O as reactants.…”

Surface Passivation by Al2O3anda-SiNx: H Films Deposited on Wet-Chemically Conditioned Si Surfaces

“…This would provide a means to combine a relatively straightforward and economically viable method of surface cleaning/conditioning with the formation of a very thin SiO 2 film and the passivation of the surface. 43,[46][47][48] In this article we extend previous work by carrying out a systematic investigation of the surface passivation induced by stacks of chemically grown SiO 2 films and PECVD a-SiN x :H and ALD Al 2 O 3 capping films. This is done for three different wet chemically grown SiO 2 films such that the passivation performance induced by the aSiN x :H and Al 2 O 3 films can be directly compared for differently prepared surfaces and for the two dielectric films.…”

“…The most common conditioning process is H-termination of Si surfaces realized by hydrofluoric acid treatments (HF-dip). The surface passivation can be subsequently realized by depositing dielectric layers such as single-layer SiO 40,43,48 It should be noted that such an ultrathin SiO 2 film can also be present when passivating an H-terminated Si surface as a native and/or interfacial SiO 2 film can grow unintentionally when H-terminated Si surfaces are exposed to the ambient (for a significant amount of time) 2,49 or when oxides (such as Al 2 O 3 ) are deposited on the Si. 14,19,50,51 From recent studies it is known that an interfacial SiO 2 layer between the passivation material and the Si has a significant effect on the surface passivation of Al 2 O 3 and a-SiN x :H films as shown for thin ALD, PECVD and thermally grown SiO 2 interlayers.…”

“…In these aspects, the results described in this article distinguish themselves from those in our previous publication. 43 Additionally, the Al 2 O 3 stacks were investigated by corona charging experiments to reveal the role of chemical passivation and field-effect passivation. This study was complemented by second harmonic generation analysis which also yields insight into the field-effect passivation.…”