Study On BTA And Particle Of Post-CMP Cleaning Of Copper Interconnection For GLSI

Copper Interconnect Chemical Mechanical Polishing?CMP?is a key process in the preparation of integrated circuits,while there are particle,organic and other defects during post CMP which affect the reliability and yield of device.In addition,low-k dielectric material is prone to delamination of the film at large mechanical pressures.Therefore,to solve the post Cu-CMP cleaning in the low pressure is significant,but also is the international problem which is faced by current microelectronics industry.In this paper,the main particle contaminant SiO₂ abrasive and the main organic pollutant source BTA are analyzed and studied during post Cu-CMP cleaning in the low pressure,including:Based on the adsorption mechanism of BTA and particle,the effectiveness of BTA and particles removal is analyzed based on chelating agent and surfactant.By comparison experiments,FA/OII chelating agent which is independent development has a better cleaning capacity compared to the international mainstream cleaning method TMAH,citric acid.Polishing machine is used to replace the PVA.The results of the comparison show that the effect of cleaning after polishing machine polishing is same as PVA brushing in conditions cleaning fluid flow rate 2L/min and brushing time 1min in conditions of the polishing speed of 55r/min,lower plate speed of 60r/min,flow rate 2L/min,polising pressure 20psi and polising time 2min.This provides a new idea for low pressure research.The effects of FA/OII chelating agent and surfactant on the removal of BTA and particles in different pressure are studied,and developed a new type of alkaline cleaning agent for low pressure conditions.This paper investigates the effect of temperature and placement time on novel alkaline cleaning agents.The chemical action of cleaning agent is related to the temperature.Temperature change,and the cleaning capacity of cleaning agent will change.The placement time is a characterization parameter for the stability of the cleaning agent.cleaning agent cleaning capacity would be reduced with the placement time increased.But there are few studies on the stability of cleaning agents.Therefore,the study of temperature and placement time on the novel alkaline cleaning agent have a strong use value.By large number of experimental studies to determine the optimal ratio we can know that:the novel alkaline cleaning agent based on 150ppm FA/OII chelating agent,30ppm FA/OI chelating agent and O-20 nonionic surfactant had a better removal ability when the temperature was 25³5?,and can meet the low roughness,surface corrosion control,low pressure requirements.This article also found that the novel alkaline cleaning agent in 1 month conditions,the cleaning effect was basically unchanged,which had a good stability.The novel alkaline cleaning agent can effectively solve particles and BTA removal problems during the post Cu-CMP cleaning in the low pressure,which was applicable to industrial applications.