The Alpsitec E 460 F CMP tool is a semi-automatic system for the polishing and the planarization of wafers. The system is compatible with 4”, 6” and 8” wafers. The tool is equipped with 4 pumps for slurry delivery and an ex-situ or in-situ conditioning system.
II. Available slurries
The slurries available at CMi are:
30N50 and Ultra Sol 7A : Basic slurry made of colloidal SiO2 particles for dielectric polishing.
30H50 : Acid slurry made of colloidal SiO2 particles for dielectric polishing. This slurry is also used to formulate slurries for metal polishing (Copper, Tungsten , Nickel ….).
40EA50 : Basic slurry for silicon polishing. It has to be used diluted 1:10 with water.
III. Examples of process
The polishing rate of the oxide is significantly dependent on the quality of the oxide. The process below is used for the qualification of the CMP tool (Uniformity and polishing rate) on blanket wafer with the slurry 30N50.
The targets are an thermal oxide is a thickness range of less than 500A (3 Sigma) for 1min30s of polishing and a removal rate between 2600 – 2800 A/min. The removal rate can be 2 to 5 times higher on deposited oxides.
This slurry can be used also for silicon, polysilicon and nitride.
The Si polishing is used after grinding. The process below is used to remove the roughness to get a miror surface for the wafer. The global removal is around 8 to 10 um for 10 min with a huge variation of the rate due to initial roughness.