Techniques for controlling precursors in chemical deposition processes

Patent metadata

Field	Value
Publication number	US-10822699-B2
Application number	US-201815946483-A
Country	US
Kind code	B2
Filing date	Apr 5, 2018
Priority date	Dec 29, 2017
Publication date	Nov 3, 2020
Grant date	Nov 3, 2020

Abstract

An apparatus for controlling precursor flow. The apparatus may include a processor; and a memory unit coupled to the processor, including a flux control routine. The flux control routine may be operative on the processor to monitor the precursor flow and may include a flux calculation processor to determine a precursor flux value based upon a change in detected signal intensity received from a cell of a gas delivery system to deliver a precursor.

First claim

What is claimed is:

1. An apparatus, comprising:
a processor; and
a memory unit coupled to the processor, including a flux control routine, the flux control routine operative on the processor to monitor a precursor flow, the flux control routine comprising:
a flux calculation processor configured to determine a precursor flux value based upon a change in detected signal intensity received from a cell of a gas delivery system to deliver a precursor;
a temperature control processor, configured to:
determine a flux error value based upon the precursor flux value;
determine a temperature adjustment ΔT, based upon the flux error value;
calculate a new set of temperature setpoints to be applied to the ampoule; and

an end-of-life processor, the end-of-life processor configured to: check for an end-of ampoule-life condition when the new set of temperature setpoints is not within the predetermined set of temperature limits.

2. The apparatus of claim 1 , the flux calculation processor configured to determine the precursor flux value by:
receiving a first reference signal in the cell, generated at a first instance, the first reference signal indicative of a detector performance at the first instance for a detector, the detector to detect a light intensity from a light source;
receiving a background signal, generated at the first instance, the background signal being generated by the detector;
receiving a second reference signal, generated at a second instance, subsequent to the first instance, the second reference signal indicative of the detector performance at the second instance for the detector; and
receiving a precursor signal, generated at a third instance, subsequent to the first instance, when the precursor is flowing in the cell.

3. The apparatus of claim 1 , the flux calculation processor configured to calculate an integrated flux of the precursor by determining the precursor flux value at a plurality of instances.

4. The apparatus of claim 2 , the temperature control processor configured to:
determine a warning band condition based upon the precursor flux value; and
adjust the temperature of an ampoule based upon the warning band condition.

5. The apparatus of claim 1 , the temperature control processor configured to adjust the temperature by:
determining a temperature adjustment ΔT, where ΔT=P*€+D*d €/dt+I*∫€/dt, where P, I and D are a proportional, integral, and derivative gains, and where € is an error based upon current temperature limits of the ampoule.

6. The apparatus of claim 1 , the temperature control processor configured to adjust the temperature by:
determining a flux error value based upon the precursor flux value;
determining a temperature adjustment ΔT, based upon the flux error value;
calculating a new set of temperature setpoints to be applied to the ampoule; and
applying the new set of temperature setpoints to control heating of the ampoule when the new set of temperature setpoints are within a predetermined set of temperature limits.

7. The apparatus of claim 6 , the flux control routine further comprising an end-of-life processor, the end-of-life processor configured to:
recalculate ΔT to generate a conservative ΔT based upon a most conservative limit when the end-of ampoule life condition has not been met; and
calculate the new set of temperature setpoints to be applied to the ampoule based upon the conservative ΔT.

8. The apparatus of claim 1 , the flux control routine further comprising an excursion processor, the excursion processor configured to:
determine a fault condition based upon the precursor flux value; and
send a notification signal of an excursion, when a substrate being processed is during the fault condition is not a first substrate.

9. The apparatus of claim 1 , the flux control routine further comprising a clog detection processor, the clog detection processor configured to:
receive a cell pressure reading for the cell;
receive the precursor flux value; and
determine a clog location based upon the cell pressure reading and precursor flux value.

10. An apparatus for controlling precursor flow, comprising:
a source to output a precursor;
a sensor assembly communicatively coupled to the source, the sensor assembly comprising:
a cell, coupled to the source, to receive and conduct the precursor;
a light source, disposed on a first side of the cell, to transmit light into the cell; and
a detector, disposed on a second side of the cell, opposite the light source, to detect light transmitted through the cell; and
a control system, the control system arranged to determine a precursor flux value based upon a change in detected light intensity received from the cell during flow of the precursor through the cell, the control system comprising:
a flux calculation processor configured to determine a precursor flux value based upon the change in detected signal intensity;
a temperature control processor, configured to:
determine a flux error value based upon the precursor flux value;
determine a temperature adjustment ΔT, based upon the flux error value; and
calculate a new set of temperature setpoints to be applied to the ampoule; and

an end-of-life processor, the end-of-life processor configured to: check for an end-of ampoule-life condition when the new set of temperature setpoints is not within the predetermined set of temperature limits.

11. An apparatus, comprising:
a processor; and
a memory unit coupled to the processor, including a flux control routine, the flux control routine operative on the processor to monitor a precursor flow, the flux control routine comprising:
a flux calculation processor configured to:
determine a precursor flux value based upon a change in detected signal intensity received from a cell of a gas delivery system to deliver a precursor; and

a clog detection processor, the clog detection processor configured to:
receive a cell pressure reading for the cell;
receive the precursor flux value; and
determine a clog location based upon the cell pressure reading and precursor flux value.

12. The apparatus of claim 11 , the flux control routine further comprising a temperature control processor, configured to determine a warning band condition based upon the precursor flux value; and adjust a temperature of an ampoule based upon the warning band condition.

13. The apparatus of claim 12 , the temperature control processor configured to adjust the temperature by:
determining an error value based upon the precursor flux value;
determining a temperature adjustment ΔT, based upon the error value;
calculating a new set of temperature setpoints to be applied to the ampoule; and
applying the new set of temperature setpoints to control heating of the ampoule when the new set of temperature setpoints are within a predetermined set of temperature limits.

14. The apparatus of claim 11 , the flux control routine further comprising an excursion processor, the excursion processor configured to:
determine a fault condition based upon the precursor flux value; and
send a notification signal of an excursion, when a substrate being processed is during the fault condition is not a first substrate.

15. The apparatus of claim 11 , the flux control routine further comprising an end-of-life processor, the end-of-life processor configured to:
check for an end-of ampoule-life condition when the new set of temperature setpoints is not within the predetermined set of temperature limits;
recalculate ΔT to generate a conservative ΔT based upon a most conservative limit when the end-of ampoule life condition

Assignees

• Varian Semiconductor Equipment Ass Inc

Inventors

• Babayan Elaina
• White Sarah
• Venugopal Vijay
• Bakke Jonathan

Classifications

• H10P95/00

  Generic processes or apparatus for manufacture or treatments not covered by the other groups of this subclass · CPC title

• H10P74/00

  Testing or measuring during manufacture or treatment of wafers, substrates or devices · CPC title

• H10P72/0604 Primary

  Process monitoring, e.g. flow or thickness monitoring · CPC title

• H10P72/0612

  Production flow monitoring, e.g. for increasing throughput · CPC title

• H10P14/6339

  deposition by cyclic CVD, e.g. ALD, ALE or pulsed CVD · CPC title