Method for treating a transport support for the conveyance and atmospheric storage of semiconductor substrates, and treatment station for the implementation of such a method

1. A treatment method of a transport support for the conveyance and storage of substrates, including a treatment stage during which a surface to be treated on the transport support is subjected to the combined action of a subatmospheric gaseous pressure and heating using intermittent infrared radiation to remove foreign bodies from said surface to be treated by alternately cutting off and restoring power to an infrared radiation source in response to a representation of the temperature of the surface to be treated so as to maintain the temperature of the surface within a predetermined difference from a temperature setting

wherein the transport support is first subjected to a primary vacuum, the subatmospheric pressure remaining greater than the pressure of the triple point of the diagram of the phases of the foreign bodies to be removed, and then the transport support is subjected to a secondary vacuum having a pressure lower than 0.1 mbar;

wherein alternately cutting off and restoring power to the intermittent infrared radiation source includes a continuous initial stage of setting the surface to be treated to a temperature which does not degrade the transport support; and

wherein the treatment method includes a conditioning stage, during which the surface to be treated is subjected to a progressive rise in gaseous pressure to around the atmospheric pressure, and to a drop in temperature to around the ambient temperature with injection of a clean gas flow, free from foreign bodies to be removed.

2. A method according to claim 1 , wherein the infrared radiation presents an emission spectrum with maximum intensities of around the absorption wavelength(s) of the foreign body or bodies to be removed.

3. A method according to claim 1 , wherein a test temperature is measured which is representative of the temperature of the surface to be treated, and the intermittent infrared radiation source is controlled in accordance with said test temperature so as to maintain said temperature of the surface to be treated at around the temperature setting.

4. The method according to claim 3 wherein the power of the infrared radiation is controlled to maintain the temperature without modifying the wavelength of the infrared radiation.

5. A method according to claim 1 , wherein said subatmospheric gaseous pressure is measured and compared with a pressure setting to control, depending on the comparison, means of adjusting the pressure to bring the subatmospheric gaseous pressure to around the pressure setting and maintain it at that level.

6. A method according to claim 1 , wherein a parameter representative of the removal of the foreign bodies from the surface to be treated is measured, and the treatment is interrupted when the representative parameter reaches a reference.

7. A treatment station for transport supports for the conveyance and storage of substrates, including:

a sealed chamber intended to be connected to pumping devices and suitable for receiving at least one transport support with a surface to be treated;

at least one source of infrared radiation, suitable for subjecting said surface to be treated to intermittent infrared radiation; and

control devices suitable for controlling the pumping devices and the source of infrared radiation for subjecting said surface to be treated to the combined action of a subatmospheric gaseous pressure and the intermittent infrared radiation, wherein said surface to be treated is subjected to a primary vacuum, the subatmospheric pressure remaining greater than the pressure of the triple point of the diagram of the phases of the foreign bodies to be removed, and then to a secondary vacuum having a pressure lower than 0.1 mbar;

wherein the power supply of the infrared radiation source is alternately cut off and restored to the intermittent infrared radiation source in response to a representation of the temperature of the surface to be treated so as to maintain the temperature of the surface within a predetermined difference from a temperature setting, including a continuous initial stage of setting the surface to be treated to a temperature which does not degrade the transport support; and

wherein the surface to be treated is subjected to a progressive rise in gaseous pressure to around the atmospheric pressure, and to a drop in temperature to around the ambient temperature with injection of a clean gas flow, free from foreign bodies to be removed.

8. A treatment station according to claim 7 , containing at least one temperature sensor, placed in the sealed chamber, and suitable for measuring a test temperature representative of the temperature of the surface to be treated.

9. A treatment station according to claim 8 , wherein the temperature sensor contains a test layer, made of a material with the same composition as the transport supports to be treated, of a low thickness, one face of which is subjected to said intermittent infrared radiation, and the opposite face of which is in contact with a temperature probe.

10. A treatment station according to claim 8 , wherein the control devices include an infrared control program, which examines the temperature data produced by the temperature sensor, which triggers the power supply of the intermittent infrared radiation source when the temperature measured by the temperature sensor is lower by more than a pre-determined difference than a temperature setting, itself lower than a maximum permissible temperature threshold, and which interrupts the power supply of the intermittent infrared radiation source whenever the temperature measured by the temperature sensor exceeds said temperature setting by more than a pre-determined difference.

11. A treatment station according to claim 7 , wherein that the intermittent infrared radiation source contains at least one source part suitable for inserting inside a transport support in the form of a box.

12. A treatment station according to claim 7 , including initial gas injection devices to inject a first localized gaseous flow in the vicinity of the surface to be treated.

13. A treatment station according to claim 7 , including second gas injection devices to inject a clean gas flow into the sealed chamber separate from the surface to be treated.

14. A treatment station according to claim 7 , containing means of measuring a parameter representative of the removal of foreign bodies from the surface to be treated, and in that the control devices are suitable for interrupting the treatment when the representative parameter reaches a reference value.

15. A treatment station according to claim 14 , wherein the means of measuring for a representative parameter include:

a scale suitable for measuring the weight of a transport support and producing a weight signal, and means of processing the weight signal to deduce from said weight signal the end of the treatment stage,

and/or a humidity and/or contaminant sensor at the outlet of the vacuum pump of the pumping devices,

and/or pressure gauges for the sealed chamber.

16. A treatment station according to claim 7 , including washing devices used to wash the transport supports directly in the sealed chamber itself.

17. A treatment station according to claim 10 , wherein the power supply of the at least one source of infrared radiation is controlled to raise and lower the temperature without modifying the wavelength of the infrared radiation.

18. A treatment station for hollow box-type transport supports for the conveyance and storage of substrates, including:

a sealed chamber intended to be connected to pumping devices and suitable for receiving at least one transport support with a surface to be treated;

at least one source of infrared radiation, suitable for subjecting said surface to be treated to intermittent infrared radiation by insertion inside the hollow box-type transport support; and

control devices suitable for controlling the pumping devices and the source of infrared radiation for subjecting said surface to be treated to the combined action of a subatmospheric gaseous pressure and the intermittent infrared radiation, wherein said surface to be treated is subjected to a primary vacuum, the subatmospheric pressure remaining greater than the pressure of the triple point of the diagram of the phases of the foreign bodies to be removed, and then to a secondary vacuum having a pressure lower than 0.1 mbar;

wherein the power supply of the infrared radiation source is alternately cut off and restored to the intermittent infrared radiation source in response to a representation of the temperature of the surface to be treated so as to maintain the temperature of the surface within a predetermined difference from a temperature setting, including a continuous initial stage of setting the surface to be treated to a temperature which does not degrade the transport support; and

wherein the surface to be treated is subjected to a progressive rise in gaseous pressure to around the atmospheric pressure, and to a drop in temperature to around the ambient temperature with injection of a clean gas flow, free from foreign bodies to be removed.