Atomic layer deposition

About: Atomic layer deposition is a research topic. Over the lifetime, 19821 publications have been published within this topic receiving 477332 citations. The topic is also known as: ALD.

Platinum single atoms on tin oxide ultrathin films for extremely sensitive gas detection

Abstract: Single atom Pt functionalized SnO2 ultrathin films are synthesized by atomic layer deposition (ALD) for application as sensing layers in resistive gas sensors. Here it is shown that the electronic conductivity of the SnO2 ultrathin films is very sensitive to the exposure to triethylamine (TEA), and that the thickness of the SnO2 films (from 4 to 18 nm) has a crucial effect on the sensor response. The 9 nm thick SnO2 film shows the best response to TEA, while a further decrease in the film thickness, i.e., 4 nm, leads to a very weak response due to the two orders of magnitude lower carrier concentration. Single atom Pt catalysts deposited on the 9 nm SnO2 film result in an unexpectedly high enhancement in the sensor response and also a decrease of the sensor working temperature. Consequently, Pt/SnO2 thin film sensors show the highest response of 136.2 to 10 ppm TEA at an optimal temperature of 200 °C (that of a pristine SnO2 film sensor is 260 °C), which is improved by a factor of 9 compared to that of pristine SnO2. Moreover, the Pt/SnO2 sensor exhibits an ultrahigh sensitivity of 8.76 ppm−1 and an extremely low limit of detection (LOD) of 7 ppb, which to our best knowledge are far superior to any previous report. Very fast response and recovery times (3/6 s) are also recorded, thus making our sensor platform highly suitable for highly-demanding applications. Mechanistic investigations reveal that the outstanding sensing performances originate from the synergistic combination of the optimized film thickness comparable to the Debye length of SnO2 and the spillover activation of oxygen by single atom Pt catalysts, as well as the oxygen vacancies in the SnO2 films.

Method of eliminating a lithography operation

Abstract: Methods of semiconductor device fabrication are disclosed. An exemplary method includes processes of depositing a first pattern on a semiconductor substrate, wherein the first pattern defines wide and narrow spaces; depositing spacer material over the first pattern on the substrate; etching the spacer material such that the spacer material is removed from horizontal surfaces of the substrate and the first pattern but remains adjacent to vertical surfaces of a wide space defined by the first pattern and remains within narrow a space defined by the first pattern; and removing the first pattern from the substrate. In one embodiment, the first pattern can comprise sacrificial material, which can include, for example, polysilicon material. The deposition can comprise physical vapor deposition, chemical vapor deposition, electrochemical deposition, molecular beam epitaxy, atomic layer deposition or other deposition techniques. According to another embodiment, features for lines and logic device components having a width greater than that of the lines are formed in the spacer material in the same mask layer.

Method of fabricating silicon-doped metal oxide layer using atomic layer deposition technique

Abstract: There are provided methods of fabricating a silicon-doped metal oxide layer on a semiconductor substrate using an atomic layer deposition technique. The methods include an operation of repeatedly performing a metal oxide layer formation cycle K times and an operation of repeatedly performing a silicon-doped metal oxide layer formation cycle Q times. At least one of the values K and Q is an integer of 2 or more. K and Q are integers ranging from 1 to about 10 respectively. The metal oxide layer formation cycle includes the steps of supplying a metal source gas to a reactor containing the substrate, and then injecting an oxide gas into the reactor. The silicon-doped metal oxide layer formation cycle includes supplying a metal source gas including silicon into a reactor containing the substrate, and then injecting an oxide gas into the reactor. The sequence of operations of repeatedly performing the metal oxide layer formation cycle K times, followed by repeatedly performing the silicon-doped metal oxide layer formation cycle Q times, is performed one or more times until a silicon-doped metal oxide layer with a desired thickness is formed on the substrate. In addition, a method of fabricating a silicon-doped hafnium oxide (Si-doped HfO 2 ) layer according to a similar invention method is also provided.

Method for forming nitride spacer by using atomic layer deposition

Abstract: The present invention provides a method for forming a silicon nitride spacer by using an atomic layer deposition (ALD) method. The procedure of the ALD is to use a first kind of excess gas as a reactant air and thus produce a first mono-layer solid phase of the first reactant air on the wafer. When the first chemical reaction is completed, the first excess air is drawn out, and then the second excess air is released to deposit a second mono-layer solid phase of the second reactant air on the first mono-layer solid phase. In this way, a whole deposited layer with a layer of the first mono-layer solid phase, a layer of the second mono-layer solid phase, and so on are stepwise formed on the wafer surface. The ALD method is a time consuming task in deposition process such as in the generation of 0.35 μm to 0.5 μm of VLSI ages. However, in the generation of 0.18 μm, 0.13 μm or beyond of VLSI ages, because the device is getting smaller than ever before, the deposition speed of the ALD method is just right on time to meet the demand and is an appropriate method in depositing silicon nitride spacer.

Method for integrated in-situ cleaning and subsequent atomic layer deposition within a single processing chamber

Abstract: A system and sequential method for integrated, in-situ modification of a substrate and subsequent atomic layer deposition of a thin film onto the substrate in an evacuated chamber comprising introducing at least one feed gas into the chamber; generating a plasma from the feed gas; exposing said substrate to ions and/or radicals formed by the plasma; modulating any ions; reacting the substrate with said modulated ions and/or radicals to remove any contaminants from the substrate and producing a modified substrate. These steps are followed, in-situ, by performing an atomic layer deposition of a thin film onto the modified substrate in the chamber including introducing a first reactant gas into said chamber; adsorbing at least one monolayer of the first reactant gas onto the modified substrate; evacuating any excess first reactant gas from the chamber; introducing at least one additional feed gas into the chamber, generating a second plasma from the additional feed gas; exposing the modified substrate to additional ions and/or radicals formed by the plasma; modulating any additional ions; and reacting the adsorbed monolayer of the first reactant gas with any modulated additional ions and/or radicals to deposit the thin film.