Design of a fast in situ infrared diagnostic tool

Conventional Fourier transform IR (FTIR) spectroscopes cannot be used to perform real time in situ IR reflection absorption spectroscopy at monolayer sensitivity for high deposition rates (a couple of tens to hundreds of nm/s) which can be obtained when using an expanding thermal deposition plasma. Therefore a new anal. tool has been developed. The tool is based on a fast optical scanner in combination with conventional grating technol. This results in a loss of spectral range with respect to FTIR spectroscopes, but a significant gain is obtained in time resoln. For the combination used this makes it possible to measure at time resoln. as low as 1.3 ms and resoln. of 24 cm-1 at 1000 cm-1. The absorption sensitivity for single reflection at the best time resoln. is approx. 10-2, but can be improved by using signal enhancement techniques. Here attenuated total reflection is used and the best sensitivity obtained is approx. 10-3, which is close to monolayer sensitivity for various absorption bands in the IR spectrum of silicon oxide films. Monolayer sensitivity can be obtained by averaging multiple spectra, however this will cause the time resoln. to decreas

Argon ion-induced dissociation of acetylene in an expanding Ar/C2H2 plasma

Mass spectrometric and Langmuir probe measurements reveal that the plasma chemistry of an expanding Ar/C2H2 plasma which is used for deposition of hydrogenated amorphous carbon is dominated by argon ion-induced dissociation of the precursor gas. The ion-induced dissociation is very efficient leading to complete depletion under certain conditions. The ion fluence as determined from modeling the mass spectrometry results is in good agreement with Langmuir probe measurements suggesting a one-to-one relation between the argon ion and acetylene consumption. The good correlation found between the growth rate and the acetylene consumption rate expresses the efficient use of the dissociation products. © 1999 American Institute of Physics. © 1999 American Institute of Physic

Proposed Route to Thin Film Crystal Si Using Biaxially Textured Foreign Template Layers

We have developed a new approach to growing photovoltaic-quality crystal silicon (c-Si) films on glass. Other approaches to film c-Si focus on increasing grain size in order to reduce the deleterious effects of grain boundaries. Instead, we have developed an approach to align the silicon grains biaxially (both in and out of plane) so that 1) grain boundaries are "low-angle" and have less effect on the electronic properties of the material and 2) subsequent epitaxial thickening is simplified. They key to our approach is the use of a foreign template layer that can be grown with biaxial texture directly on glass

A new and fast in-situ spectroscopic infrared absorption measurement technique

Silicon oxide like films are deposited using an expanding thermal plasma (cascaded arc) in combination with HMDSO and oxygen as deposition precursors. These films are deposited at high rate (up to 200 nm/s). In general Fourier transform infrared (FTIR) reflection absorption spectroscopy is a useful tool for in situ analysis of the film deposition growth process [1,2]. However this technique is difficult to apply when the film deposition rate is reaching high values (10 to 100 nm/s). At this rate the time to deposit a monolayer of film material is approximately 3 to 30 ms, whereas the typical time to make a single scan by means of FTIR is 0.1 - 1.0 s, which is almost two orders of magnitude longer than the monolayer deposition time. This excludes FTIR spectroscopy as a means to study e.g. initial growth effects. Therefore to study the monolayer or submonolayer growth of films deposited at high deposition rates by means of infrared reflection absorption spectroscopy it is necessary to use another technique instead of FTIR. To improve the speed of the measuring technique an offer has to be made. FTIR spectroscopy normally measures a broadbanded spectrum (typical for infrared spectroscopy 500 to 7500 cm-1), therefore it is possible to investigate the behaviour of various absorption peaks at the same time. However to gain scanning speed, it is necessary to concentrate on one single absorption peak, i.e. reducing the spectral range

A new and fast in-situ spectroscopic infrared absorption measurement technique

Silicon oxide like films are deposited using an expanding thermal plasma (cascaded arc) in combination with HMDSO and oxygen as deposition precursors. These films are deposited at high rate (up to 200 nm/s). In general Fourier transform infrared (FTIR) reflection absorption spectroscopy is a useful tool for in situ analysis of the film deposition growth process [1,2]. However this technique is difficult to apply when the film deposition rate is reaching high values (10 to 100 nm/s). At this rate the time to deposit a monolayer of film material is approximately 3 to 30 ms, whereas the typical time to make a single scan by means of FTIR is 0.1 - 1.0 s, which is almost two orders of magnitude longer than the monolayer deposition time. This excludes FTIR spectroscopy as a means to study e.g. initial growth effects. Therefore to study the monolayer or submonolayer growth of films deposited at high deposition rates by means of infrared reflection absorption spectroscopy it is necessary to use another technique instead of FTIR. To improve the speed of the measuring technique an offer has to be made. FTIR spectroscopy normally measures a broadbanded spectrum (typical for infrared spectroscopy 500 to 7500 cm-1), therefore it is possible to investigate the behaviour of various absorption peaks at the same time. However to gain scanning speed, it is necessary to concentrate on one single absorption peak, i.e. reducing the spectral range

Design of a fast in situ infrared diagnostic tool

Conventional Fourier transform IR (FTIR) spectroscopes cannot be used to perform real time in situ IR reflection absorption spectroscopy at monolayer sensitivity for high deposition rates (a couple of tens to hundreds of nm/s) which can be obtained when using an expanding thermal deposition plasma. Therefore a new anal. tool has been developed. The tool is based on a fast optical scanner in combination with conventional grating technol. This results in a loss of spectral range with respect to FTIR spectroscopes, but a significant gain is obtained in time resoln. For the combination used this makes it possible to measure at time resoln. as low as 1.3 ms and resoln. of 24 cm-1 at 1000 cm-1. The absorption sensitivity for single reflection at the best time resoln. is approx. 10-2, but can be improved by using signal enhancement techniques. Here attenuated total reflection is used and the best sensitivity obtained is approx. 10-3, which is close to monolayer sensitivity for various absorption bands in the IR spectrum of silicon oxide films. Monolayer sensitivity can be obtained by averaging multiple spectra, however this will cause the time resoln. to decreas

Expanding thermal plasma deposition of silicon dioxide-like films for microelectronic devices

n this paper we report on the use of the expanding thermal plasma (ETP) technique for the deposition of carbon-free SiO2 films by means of hexamethyldisiloxane (HMDSO)/oxygen mixtures, at a growth rate of 8-10 nm/s. Information concerning the film chemical properties and refractive index/growth rate have been obtained by means of FTIR measurements and in situ single wavelength ellipsometry, respectively. Because of its geometry, the ETP configuration has proven its suitability for studies concerning the fragmentation paths of the HMDSO molecule and the reactions occurring in the plasma phase. In this framework, very recent results obtained by coupling the SiO2 film-deposition set up with a very sensitive, high spectral resolution- absorption technique, Cavity Ring Down Spectroscopy, are presented

Deposition of organosilicon thin films using a remote thermal plasma

Organosilicon thin films have been deposited using a remote plasma produced from an expanding thermal plasma. Hexamethyldisiloxane and oxygen have been used as precursor gases. It is shown that it is possible to deposit organosilicon thin films at high deposition rates (>60nm/s). The film refractive index (at 632.8 nm) is a result of the presence of voids and carbon in the film. Analysis of the deposited films by means of elastic recoil detection analysis and Fourier transform infrared spectroscopy shows that the dissociation and deposition mechanism is complex. The deposited films contain carbon which is chemically bonded is a methyl configuration. From this fact the plasma gas phase chemistry and the surface chemistry have been hypothesized. The film deposition rate increases with a decrease in substrate temperature, which is highly beneficial for deposition or organosilicon thin films on substrate materials with low melting temperatur