Specific Process Knowledge/Thin film deposition/Cluster-based multi-chamber high vacuum sputtering deposition system: Difference between revisions

Chamber PC1 consists of six KJLC Torus® 3" magnetron sputtering sources with possibility of RF, DC, Pulse DC and HIPIMS sputtering. There are Argon, Nitrogen and Oxygen gas lines connected to this chamber. The chamber allows RF bias on the substrate, which can be used for substrate cleaning before the deposition or used during the deposition to alter the film properties. Deposition of magnetic materials requires the high strength magnet (HSM), which must be installed on source 3 in PC1. It is possible to do co-sputtering (sputtering of two or more sources at the same time) as long as the sources are not sharing the same power supply.  

image:PC1_photo.png| Photography of the chamber.

The second process chamber called PC3 consists of two KJLC Torus® 3" magnetron sputtering sources and one height-adjustable KJLC Torus® 4" magnetron sputtering source, also with the possibility of RF, DC, Pulse DC and HiPIMS sputtering. The chamber has a possibility to do the RF bias on a substrate, which can be used as substrate cleaning before the deposition or used during the deposition to alter the film properties. It is possible to do the co-sputtering (sputtering of two or more sources at the same time) as long as the sources are not sharing the same power supply. The chamber is equipped with a residual gas analyzer (RGA) that allows monitoring post-process chemical gas traces. In order to operate the analyzer, the chamber should be pumped to base pressure.

image:PC3_photo.png| Photography of the chamber.

The load-lock and process chambers PC1 and PC3 are all connected through the common distribution chamber. The robot arm can transfer the sample to the selected destination. During normal operation, the chamber is pumped to a base pressure ensuring the safe transfer of the sample between chambers and load-lock without breaking a vacuum. The unit is conectedto its own turbo-pump.

image:arm_robot_distribution_chamber.png| The photography of the distribution chamber with and without the top cover.

The load-lock chamber is the only part of the tool which can be accesed by user. Ventilation and pumping takes approximately 5 min. The chamber has its own turbo pump. Inside there is a shelf - a cassete with 10 slots. The images below shows the load-lock set-up and sample mounting. The shelf is designed to handle 6-inch wafers, which has to be placed into dedicated carrier rings. Those rings with wafers can be introduced to the cassete - shelf. Different adapter-holders can be used for operating with 4-inch wafers and small chips. After the load-lock is pumped it takes approx. 6 min tol transfer the sample into the process chamber and 8 min to return back.

image:Kaempe_Lesker_Load_Loak_image1.png| The load-lock chamber.

<b>Attention!</b> The shelf turns opposite side from when the carrier ring is loading in. Furthermore, the shelf has to be placed properly inside the load lock chamber. A carrier ring without sample should never be loaded in the load lock. The light in the load lock chamber can be turned on. The light switch is located on the left side of the load-lock. Process chambers PC 1 and PC 3 are also equipted with light switches.

Table below shows the maximum power and maximum ramp up/down power for available materials:   

Additinal information about the processes and equipment performace can be found here:

There are 76 developed and tested process recipes for general users (48 for PC1 and 28 for PC3). They include convenient and reative DC, RF and PulseDC sputtering with or without substrate bias. Deposition using HiPIMS can only be done with DTU Nanolab staff assistance. Starting the recipe the user can change the relevant process parameters: power, pressure, reactive gas ratio, rotation speed, substrate bias etc. Each of these 76 recipes has a unique name which indicates the process chamber, type of sputtering (DC, RF, or Pulse DC) gas flow control, the type of reactive gas and the presence of substrate bias. In addition to the standard process recipes, there are also recipes for substrate heating and RF cleaning.

image:Kaempe_Lesker_standard_recipe_name.png| The standard recipe has its own unic name starting with letters "MD" which stands for "Master Deposition".

So far following results can be used as a guide or reference:

There are software interlocks that will not allow the transfer port to open while the heater is on. Also, it will not allow the heater to turn on if there are no assigned wafer in the chamber, and also will not allow the chamber vent valve to open if the temperature shows above 80 degrees Celsius.  

A sample transferring can be done while the sample is hot but not while the heater is on.  The heater thermocouples will cool very rapidly as soon as the heater is turned off so there is no set temperature. A sample transfer unload should be done when the temperature is below 300 degrees Celsius.

The RF cleaning can be used to clean the sample before the deposition. There are depicted recipes for that:

The advance system with the cassette loader and robot arm, allow running a batch process ("Master Cassette" recipes). These processes are not among the standard recipes but can be developed by DTU Nanolab upon request.