Embodiments described herein generally relate to an in-situ metrology system that can constantly provide an uninterrupted optical access to a substrate disposed within a process chamber. In one embodiment, a metrology system for a substrate processing chamber is provided. The metrology system includes a sensor view pipe coupling to a quartz dome of a substrate processing chamber, a flange extending radially from an outer surface of the sensor view pipe, and a viewport window disposed on the flange, the viewport window having spectral ranges chosen for an optical sensor that is disposed on or adjacent to the viewport window.

Embodiments described herein generally relate to an in-situ metrology system that can constantly provide an uninterrupted optical access to a substrate disposed within a process chamber. In one embodiment, a metrology system for a substrate processing chamber is provided. The metrology system includes a sensor view pipe coupling to a quartz dome of a substrate processing chamber, a flange extending radially from an outer surface of the sensor view pipe, and a viewport window disposed on the flange, the viewport window having spectral ranges chosen for an optical sensor that is disposed on or adjacent to the viewport window.

A processing chamber includes a chamber body, a substrate support configured to hold a substrate in place, and a pre-heat ring having a central opening sized to be disposed around the substrate. A process gas inlet is configured to direct process gas in a lateral direction to flow over the pre-heat ring and the substrate. A process gas flow deflector includes a radially outer mounting portion and a radially inner blade-shaped process gas deflection portion extending in a radial direction. The radially inner blade-shaped process gas deflection portion is shaped as a ring segment. The radially inner blade-shaped process gas deflection portion is disposed above the process gas inlet and dimensioned to overlap with the pre-heat ring, wherein a degree of overlap between the pre-heat ring and process gas flow deflector in the radial direction is at least ½ of the radial dimension of the pre-heat ring.

Reducing the microvoid (MV) density in AlN ameliorates numerous problems related to cracking during crystal growth, etch pit generation during the polishing, reduction of the optical transparency in an AlN wafer, and, possibly, growth pit formation during epitaxial growth of AlN and/or AlGaN. This facilitates practical crystal production strategies and the formation of large, bulk AlN crystals with low defect densities—e.g., a dislocation density below 10.sup.4 cm.sup.−2 and an inclusion density below 10.sup.4 cm.sup.−3 and/or a MV density below 10.sup.4 cm.sup.−3.

Reducing the microvoid (MV) density in AlN ameliorates numerous problems related to cracking during crystal growth, etch pit generation during the polishing, reduction of the optical transparency in an AlN wafer, and, possibly, growth pit formation during epitaxial growth of AlN and/or AlGaN. This facilitates practical crystal production strategies and the formation of large, bulk AlN crystals with low defect densities—e.g., a dislocation density below 10.sup.4 cm.sup.−2 and an inclusion density below 10.sup.4 cm.sup.−3 and/or a MV density below 10.sup.4 cm.sup.−3.

The present invention relates to an apparatus for growing crystals. The apparatus comprises a chamber and a crucible being arranged in a heatable accommodation space of the chamber, wherein the crucible comprises an inner volume which is configured for growing crystals inside. The crucible comprises a bottom from which respective side walls extend to a top section of the crucible. The crucible comprises at least one a deposition section which is configured for attaching a seed crystal, wherein the deposition section is formed on at least one of the side wall and the top section of the crucible.

A cyclical epitaxial deposition system and a gas distribution module are provided. The gas distribution module includes an inflow element having a plurality of inlet holes, a guide assembly, and an outflow element. The guide assembly disposed between the inflow and outflow elements includes a plurality of guide channels separate from one another and a plurality of temporary gas retention trenches respectively corresponding to the guide channels. Each of the guide channels is in fluid communication with the corresponding inlet hole. The outflow element has a plurality of diffusion regions respectively corresponding to the gas retention trenches, and a plurality of outlet channels respectively corresponding to the diffusion regions. Each of the diffusion regions has a plurality of diffusion apertures, and each of the temporary gas retention trenches is in fluid communication with the corresponding outlet channel through the diffusion apertures in the corresponding diffusion region.

A vapor phase growth device includes a flow channel defining a space through which a source gas for forming an epi layer flows, a susceptor configured to hold a substrate in a state where the substrate faces the space, and a first member disposed vertically above and opposite to the susceptor, the first member having a thermal expansion coefficient not less than 0.7 times and not more than 1.3 times the thermal expansion coefficient of the substrate. The flow channel includes a holding portion configured to hold the first member.

The method serves for depositing a layer of silicon carbide with n-type doping onto a surface of a substrate placed horizontally on a rotating susceptor inside a reaction chamber by means of a CVD type process; the rotating susceptor is adapted to single-substrate support; the method includes introducing and flowing a gaseous mixture internally along the reaction chamber from a first side to a second side passing over a portion of a lower wall of said reaction chamber and then over said rotating susceptor supporting one substrate; the gaseous mixture comprises or consists of: one or more gases being precursor of silicon carbide to be deposited and a carrier gas and a precursor gas containing a substance adapted to give rise to n-type doping; the dopant substance is adapted to be subjected to pyrolysis catalysed by contact with an internal surface made of silicon carbide of said reaction chamber forming species with stoichiometry NHxCySiz where x and y and z are comprised between 0 and 3 and x+y+z>0, the reaction chamber is at a temperature comprised in the range between 1450° C. and 1800° C. and at a pressure comprised in the range between 5 kPa and 30 kPa; the substrate is placed inside the reaction chamber in a region where trends in availability respectively of Si, C and N are all decreasing and where temperature is within a deposition temperature range.

The method serves for depositing a layer of silicon carbide with n-type doping onto a surface of a substrate placed horizontally on a rotating susceptor inside a reaction chamber by means of a CVD type process; the rotating susceptor is adapted to single-substrate support; the method includes introducing and flowing a gaseous mixture internally along the reaction chamber from a first side to a second side passing over a portion of a lower wall of said reaction chamber and then over said rotating susceptor supporting one substrate; the gaseous mixture comprises or consists of: one or more gases being precursor of silicon carbide to be deposited and a carrier gas and a precursor gas containing a substance adapted to give rise to n-type doping; the dopant substance is adapted to be subjected to pyrolysis catalysed by contact with an internal surface made of silicon carbide of said reaction chamber forming species with stoichiometry NHxCySiz where x and y and z are comprised between 0 and 3 and x+y+z>0, the reaction chamber is at a temperature comprised in the range between 1450° C. and 1800° C. and at a pressure comprised in the range between 5 kPa and 30 kPa; the substrate is placed inside the reaction chamber in a region where trends in availability respectively of Si, C and N are all decreasing and where temperature is within a deposition temperature range.