METHOD OF CHEMICAL-MECHANICAL POLISHING OF THICK LAYERS OF COBALT-CONTAINING ALLOYS Russian patent published in 2019 - IPC C23F1/28 C23F3/04 C23F11/06 C09G1/02 H01L21/02 

FIELD: chemistry.

SUBSTANCE: method for chemical-mechanical polishing of a thick layer of a ferromagnetic cobalt-containing alloy on the surface of a plate of silicon oxide with an etched groove involves processing the plate with a polishing pad in the presence of a suspension in two steps, which ensures uniform removal of the material and obtaining a given thickness of the alloy in said groove. At the first stage, polishing is carried out at rate of 400–600 nm/min at pressure of 6.9–10.3 kPa and a suspension feed rate of 150 ml/min, wherein a polishing acid suspension containing aluminum oxide, amorphous silicon dioxide, nitric acid and water, to which is added H₂O₂ to achieve concentration of H₂O₂ 0.6–1.8 wt. % and pH 2–3. At second step, polishing is carried out at pressure of 15.9–19.3 kPa and suspension feed rate of 300 ml/min, using a polishing alkaline suspension containing silicon dioxide, inorganic hydroxide and water, to which is added H₂O₂ to achieve concentration of 0.8–1.2 wt. % and pH 9.5-11.2.

EFFECT: invention relates to chemical-mechanical polishing of thick layers of ferromagnetic cobalt-containing alloys and can be used in making elements of devices and devices in micro- and nanoelectronics.

10 cl, 3 dwg