Thermal CVD/PECVD reactor and use for thermal chemical vapor deposition of silicon dioxide and in-situ multi-step planarized process

A semiconductor processing reactor comprising:

• a housing defining a chamber therein for mounting a wafer horizontally;
• vacuum exhaust pumping means communicating with the chamber;
• a horizontal inlet gas manifold oriented horizontally over the wafer mounting position for supplying reactant gases to a wafer at the mounting position;
• the manifold also comprising a first central array of holes for dispensing the reactant gas downward to the wafer and a second peripheral array of holes for directing purging gas downward to the periphery of the wafer, the first and second arrays of holes each comprising a number of generally concentric rings with the first central array having random within-ring hole spacing for limiting the number of radially aligned holes and the second peripheral array having a radially staggered pattern to ensure no ring-to-ring radial alignment of holes.

A semiconductor processing reactor adapted for single step and in-situ multiple step processing sequences selected from thermal chemical vapor deposition, plasma-enhanced chemical vapor deposition, plasma-assisted etchback, plasma self-cleaning and topography modification by sputtering with uniform wafer processing over a wide range of high pressures .ltoreq. one atmosphere, comprising:

• a housing defining a chamber for mounting a wafer for processing at a selected position therein;
• a first gas inlet manifold positioned above the selected position, the manifold having a center gas outlet region adapted for directing reactant gases downwardly to a wafer at the selected position and an outer peripheral region adapted for directing purging gas toward the wafer periphery;
• a second gas inlet manifold located at the bottom of the chamber and adapted for directing purging gas upwardly and across the wafer;
• means for circulating fluid at a controlled temperature within the first gas inlet manifold for maintaining the internal surfaces within a selected temperature range for preventing condensation, decomposition and reaction of said gases therein and for maintaining the external wafer adjacent surface above a selected temperature range for suppressing unwanted deposition thereon;
• a radial gas flow pumping means comprising vacuum exhaust pump means gas;
• a distributor plate mounted peripherally about the wafer mounting position within the chamber, the plate including a circular array of exhaust holes therein;
• a circular channel formed in the housing communicating with the exhaust holes and having an exhaust port connected to the vacuum exhaust pump means for flowing said deposition gases radially across the wafer and through the exhaust port, said channel volume providing conductance sufficient to enable controlled radial gas flow across the wafer to the exhaust holes;
• a thin high emissivity susceptor;
• movable susceptor support means mounting the susceptor in a horizontal orientation and adapted for moving vertically for selectively positioning the susceptor and a wafer positioned thereon parallel to the gas manifold at selected positions closely adjacent the gas manifold;
• a transparent window forming the bottom of the chamber;
• radiant heating means mounted to the housing beneath the window comprising lamps and a circular reflector module mounting the lamps in a circular array for directing a collimated beam of radiant energy through the transparent window onto the susceptor with an incident power density substantially higher at the edge of the susceptor than at the center thereof;
• and
• a gas feed-through device connected to the first gas inlet manifold, comprising tube means having inlet and outlet ends and being adapted for providing coaxial flow of deposition gas on the inside thereof and purge gas on the outside thereof into the first manifold, the tube means being adapted for connection to ground at an inlet end and to an RF power supply at the outlet or manifold end for applying RF power to the gas inlet manifold, and the tube means also having a controlled electrical impedance along its length for establishing a constant voltage gradient along said length to prevent breakdown of the gas therein.

A semiconductor processing reactor comprising:

• a housing defining a chamber therein adapted for the gas chemistry processing of a wafer within the chamber;
• a transparent window forming the bottom of the chamber;
• and
• a thin, high emissivity susceptor positioned within the chamber for supporting a wafer;
• the housing further comprising:
• radiant heating means mounted to the housing beneath the window, comprising:
• a circular array of lamps and a reflector module having an annular reflecting channel therein aligned with the periphery of the susceptor, the reflector module mounting the lamps in a general vertical orientation in a circular array within the channel for directing a substantially collimated beam of radiant energy from the lamps through the transparent window onto the susceptor with an incident power density substantially higher at the edge of the susceptor than at the center thereof.

A semiconductor processing reactor comprising:

• a housing defining a chamber therein adapted for the gas chemistry processing of a wafer within the chamber;
• said housing further including:
• a first gas inlet manifold positioned above the wafer and a second gas inlet manifold located at the bottom of the chamber, the first manifold having a center region adapted for directing deposition gas downwardly to the wafer and an outer peripheral region adapted for directing purging gas downwardly to the wafer periphery, and the second manifold being adapted for directing purging gas upwardly to the wafer periphery;
• and
• means for exhausting undeposited gases radially away from the wafer.

A chemical vapor deposition reactor, comprising:

• a housing defining a chamber therein and being adapted for the chemical vapor deposition of a layer on a wafer within the chamber, and including a gas inlet manifold for supplying deposition gases to the chamber and an RF power supply and matching for forming a deposition gas plasma within the chamber to deposit the layer on the wafer;
• and
• the housing further including a combined RF/gas feed-through device connected to the gas inlet manifold and comprising:
• tube means having inlet and outlet ends and being adapted for providing co-axial flow of deposition gas on the inside thereof and purge gas on the outside thereof into the gas inlet manifold, the tube means being adapted for connection to ground at the inlet end and to an RF power supply at the outlet or manifold end, and the tube means also having a controlled electrical impedance along its length for establishing a constant voltage gradient along said length to prevent breakdown of the gas.

A semiconductor processing reactor comprising a housing defining a vacuum chamber therein adapted for the chemical vapor deposition of a layer on a wafer positioned within the chamber, the housing having a closable opening therein for receiving a wafer-holder blade to insert a wafer into the chamber and remove the wafer from the chamber;

• the housing further comprising:
• a first, vertically movable, generally circular horizontal array of fingers adapted for holding the wafer;
• a second, vertically movable, generally circular horizontal array of fingers interdigitated with the first fingers, the second fingers being adapted for holding a thin generally circular susceptor in a horizontal orientation;
• a first vertically movable elevator mechanism mounting the first fingers and for moving the first fingers (a) upwardly to lift the wafer off the blade preparatory to lifting movement of the second fingers into a processing position and (b) downwardly to return the wafer to the blade;
• and
• a second, vertically movable elevator mechanism mounting the second fingers for moving the second fingers (c) upwardly past the first fingers to lift the wafer therefrom and onto the susceptor and into the said processing position, and (d) downwardly for depositing the processed wafer onto the first fingers preparatory to return by the first fingers to the blade.

A chemical vapor deposition reactor system comprising:

• a housing forming a vacuum chamber, said housing having a first horizontal gas manifold adapted for introducing reaction gas into the chamber;
• a first, vertically movable elevator mechanism;
• a first, vertically movable, generally circular horizontal array of fingers adapted for holding a wafer;
• a second, vertically movable elevator mechanism;
• a second, vertically movable, generally circular horizontal array of fingers interdigitated with the first fingers, the second fingers being adapted for holding a thin generally circular susceptor in a horizontal orientation;
• a first, vertically movable elevator mechanism mounting the first fingers for moving the first fingers (a) upwardly to lift the wafer off the blade preparatory to lifting movement of the second fingers into a processing position and (b) downwardly to return the wafer to the blade;
• and
• a second, vertically movable elevator mechanism mounting the second fingers for moving the second fingers (c) upwardly past the first fingers to lift the wafer therefrom and onto the susceptor and into the said processing position, and (d) downwardly for depositing the processed wafer onto the first fingers preparatory to return by the first fingers to the blade;
• the bottom of said chamber comprising a quartz window;
• radiant heating means mounted to the housing beneath the window and comprising a circular array of quartz-tungsten-halogen lamps and a reflector module having an annular reflecting channel therein aligned with the periphery of the horizontal susceptor, the reflector module mounting the lamps in a general vertical orientation in a circular array within the channel, for directing a substantially-collimated beam of near-IR radiant energy from the lamps through the quartz window onto the susceptor with a power density substantially higher at the edge of the susceptor than at the center thereof;
• the manifold comprising a first central array of holes for dispensing deposition gas, and further comprising a second peripheral array of holes for directing purging gas downward to the periphery of the wafer;
• the first and second arrays of holes each comprising a number of generally concentric rings with the first central array having random hole spacing within each ring for controlling the number of radially aligned holes;
• and the second peripheral array having an approximately equal number of holes in each ring arranged in a radially staggered pattern free of ring-to-ring radial alignment of holes;
• an annular second inlet manifold positioned around the bottom of the chamber adjacent the quartz window for directing purge gas into the chamber;
• an annular exhaust channel defined within the housing about the periphery of the wafer deposition position;
• vacuum means coupled to the annular exhaust chamber for applying a vacuum to the chamber, whereby application of the vacuum and application of purge gas to the first and second manifolds causes a first purge gas flow downwardly from the first manifold to the outer periphery of the wafer and a second purge gas flow from the second manifold sweeping across the quartz window, then upwardly past the bottom edge of the wafer, said two flows merging and flowing out of the chamber, thereby removing spent deposition gas and entrained products;
• the susceptor being connected to ground;
• and
• the reactor also comprising a deposition gas feed-through device connected to the first manifold, comprising:
• tube means having inlet and outlet ends and being adapted for providing co-axial flow of deposition gas on the inside thereof and purge gas on the outside thereof into the first manifold, the tube means being adapted for connection to ground at the inlet end and to an RF power supply at the outlet or manifold end, and the tube means also having a controlled electrical impedance along its length for establishing a constant voltage gradient along said length to prevent breakdown of the gas therein.