Specific Process Knowledge/Thermal Process/RTP Jipelec 2: Difference between revisions

[[index.php?title=Category:Equipment|Thermal Jipelec]]

[[index.php?title=Category:Thermal process|Jipelec]]

The machine consists of a reactor chamber, in which different samples can be processed/annealed at temperatures up to 1100 °C.

The temperature of the substrate can be controlled by two different modes. The preferred one is called the closed loop mode, i.e. the temperature control mode (pyrometer or thermocouple control). On the other hand, an open loop mode (power control mode), although possible, is not recommended to be used as default. In the latter, the temperature of the substrate would vary according to the power emitted by the lamps that is established as setpoint, without any limiting check from the pyrometer or thermocouple. Thus, it can happen that the chamber is heated up very fast with no actual temperature control, which can induce serious damages to the tool.

In RTP2 Jipelec, the pyrometer (Pyro1) is used as the default control sensor and it is always present. The thermocouples are not intended to be used for high-temperature processes - at 1000 °C or above - as a lifetime reduction can be expected if they are used in such conditions. As such, the thermocouple (TC1) should only be mounted and used as temperature control if the process temperature ranges RT to 150 °C. Mounting the thermocouples must only be carried out by the responsible persons - users do not need to know how to do it.

Nonetheless, while processing, it is possible to have up to three thermocouples measuring the temperature - TC1, TC2 and TC3 - in conjugation with the optical pyrometer. A short description of each component can be found below.

*'''TC1 (optional)''' - This is called the control thermocouple, only mounted when temperatures ranging RT to 150 °C are needed. When using a susceptor, it corresponds to a long, thin TC that is placed in a hole at the edge of the susceptor. On the other hand, if a wafer is directly placed on top of the quartz pins or a carrier wafer is being used, it is not possible to use this long TC. Thus, TC1 corresponds to a thick TC positioned in contact with the back of the wafer/carrier, approximately in the center. Regardless its type, it is very important that the TC is placed correctly and that contact with the substrate is ensured, otherwise the temperature measurement will not be correct.

*'''Optical Pyrometer (mandatory)''' - The pyrometer is making an non-contact optical temperature measurement in the center of the susceptor or wafer. To ensure that the temperature measured by the pyrometer is correct, a temperature calibration must be done, for which the TC1 is used as a reference. To get the most correct temperature measurement, a pyrometer calibration should be done for each substrate type (thickness, size, material, etc.).

The machine has a PID regulator for the temperature control. For each substrate type, thickness, size, material and desired process these PID settings have to be optimized in order to ensure that the actual temperature matches the settings as good as possible and no damage is induced to the tool while processing.

!style="background:Silver; color:black" align="center" align="center" rowspan="3"|Temperature

* 400 ^oC to 1100 ^oC (Si-based wafer)

|style="background:Silver; color:black" rowspan="2"|Thermocouple Control

* '''Vacuum''' --> Room temperature to 400 ^oC

* '''No vacuum''' --> Room temperature to 1000 ^oC

! rowspan="7" |Process time

| style="background:Silver; color:black" |At 1100 ^oC

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*III-V materials - '''these cannot be heated above 450 °C,''' otherwise it can lead to outgassing of toxic gases. For that reason, '''III-V samples are limited to a maximum process temperature of  400 °C.'''

The '''user manual''', user '''APV''', '''technical documents and contact information''' can be found in LabManager: '''[http://www.labmanager.dtu.dk/function.php?module=Machine&view=view&mach=459 RTP2 Jipelec]'''