Active pulse monitoring in a chemical reactor

An apparatus for supplying repeated vapor phase reactant pulses to a reaction chamber, the apparatus comprising:

• a reactant source;
• a gas conduit system that connects the reactant source and the reaction chamber;
• a valve positioned in the gas conduit system such that switching of the valve induces vapor phase reactant pulses from the reactant source to the reaction chamber;
• a first sensor that is in communication with the gas conduit system at a position upstream of the reaction chamber and provides a first signal indicative of a first characteristic parameter of the reactant pulses at the position upstream of the reaction chamber as a function of time;
• and
• a diagnostic and control unit that is configured to generate a first curve from the first sensor and to monitor changes over time in a shape of the first curve during subsequent reactant pulses.

A method for determining changes in a reactant supply system that is designed to supply repeated pulses of a vapor phase reactant to a reaction chamber of an ALD system, the method comprising:

• providing a reactant source that comprises a solid and/or liquid reactant and a vaporizing mechanism;
• providing a conduit system to connect the reactant source to the reaction chamber and to connect a purging gas source to the reaction chamber;
• providing at least one valve positioned in the conduit system such that switching of the valve induces alternating vapor phase reactant pulses from the reactant source to the reaction chamber and purging pulses from the purging gas source;
• repeatedly switching the valve to induce repeated alternating vapor phase reactant and purging pulses;
• providing a first sensor that is in communication with the gas conduit system and provides a first signal indicative of a first parameter in the gas conduit system;
• generating a first curve from the first signal as a function of time, the first curve having a shape characteristic of the repeated vapor phase reactant and purging pulses while the reactant and purging pulses are being supplied to the reaction chamber;
• monitoring the shape of the first curve to determine changes indicative of changes in a supply of repeated reactant pulses to the reaction chamber;
• and
• in response to the changes in the shape of the first curve, replacing the reactant source with a second reactant source that comprises a solid and/or liquid reactant and a vaporizing mechanism.

A method for determining changes in an amount of reactant in a first reactant source within an atomic layer deposition (ALD) system, the method comprising:

• monitoring pressure in a conduit that communicates with a reactant source container in the ALD system;
• generating a pressure signal corresponding to the monitored pressure during at least a first ALD cycle comprising a pulse of a first reactant and a pulse of a second reactant and at least a second ALD cycle separated in time from the first ALD cycle and comprising a pulse of the first reactant and a pulse of the second reactant;
• comparing a pattern of the pressure signal over time during at least a portion of the first ALD cycle to a pattern of the pressure signal over time during at least a portion of the second ALD cycle;
• and
• measuring if there is a significant difference in the pattern of the pressure signal between the first ALD cycle and the second ALD cycle to determine the amount of the first reactant in the first reactant source.