Energy transferred to the substrate surface during reactive magnetron sputtering of aluminum in Ar/O2 atmosphere

International audienceA study of the reactive sputtering of aluminum was carried out by coupling energy flux measurements at the substrate location with conventional diagnostics of the gas phase and analyses of the deposited films. The main purpose was to get some insight into the elementary mechanisms involved at the substrate surface during the film growth in the well known metal and oxide regimes and at the transitions from one to another. Measurements were carried out in front of a 10 cmAl target at a power of 400W (i.e. 5 W/cm2) and a total pressure of 0.6 Pa. The flow rate ratio (O2/O2+Ar) was varied in the range 0 to 50 %. Different kinetics and values of energy transfer, denoting different involved mechanisms, were evidenced at metal-oxide (increasing flow rate) and oxide-metal (decreasing flow rate) transitions. The metal-oxide transition was found to be a progressive process, in agreement with optical emission spectroscopy and deposit analysis, characterized by an increase of the energy flux that could be due to the oxidation of the growing metal film. On the contrary, oxide-metal transition is abrupt, and a high energy released at the beginning that could not be attributed to a chemical reaction. The possible effect of O-ions at this step was discussed

A new generation of cryogenic processes for silicon deep etching

International audienceDeep etching of silicon is intensively used in microtechnology for MEMS and power microelectronic components. At GREMI, we study and develop the cryoetching process, which is a good alternative in terms of rapidity and cleanliness compared to other processes (e.g. Bosch process). The reactor is an ICP where the wafer is cooled down to a very low temperature (about -100°C). SF6 and O2 are the basic gases involved in the process. O2 (10 %) is used to form an SiOxFy passivation layer, which grows on vertical sidewalls not submitted to ion bombardment. This oxidation occurs very efficiently at very low temperature of the substrate. The perfect control of this passivation layer formation is a key issue in the cryogenic process. Mass spectrometry measurements give the evolution of the oxidation threshold (necessary oxygen proportion to form the passivation layer) as a function of temperature, RF power and bias. The role of the etch by-products (SiF4) in the formation of the SiOxFy layer was investigated using ellipsometry and mass spectrometry. With this study, we were able to develop new processes based on steps of SiF4/O2 plasmas to enhance the passivation layer deposition and efficiency

CARACTERISATION D'UN PLASMA DE CARBONE FORTEMENT IONISE CREE PAR DECHARGE CAPILLAIRE ABLATIVE EN VUE DE LA PRODUCTION DE SOURCES X COHERENTES - LASER X - ET INCOHERENTES

ORSAY-PARIS 11-BU Sciences (914712101) / SudocSudocFranceF

Deep etching processes for silicon micro- and nano-machining

PosterInternational audienc

A Heat Flux Microsensor for Direct Measurements in Plasma Surface Interactions

International audienc