Polyurethane-material polishing pad and preparation method thereof

Abstract

The invention relates to a polyurethane-material polishing pad and a preparation method thereof. By adoption of the polyurethane-material polishing pad and the preparation method, the problems of high energy consumption, long period, high production cost and poor degradability in the existing process are solved. The polyurethane-material polishing pad comprises a polishing layer, a buffering layer and a transparent bottom pad, wherein the polishing layer is formed by mixing, forming and curing isocyanic acid radical ion end-blocking energy-saving prepolymer A, polyatomic alcohol B, a curing agent C and hollow polymer microspheres D; the mixing ratio of the isocyanic acid radical ion end-blocking energy-saving prepolymer A to the polyatomic alcohol B to the curing agent C to the hollow polymer microspheres D is (5-100):(5-100):(5-50):(0.15-10); the shore hardness of the polishing layer is 41D-90D, the density is 0.7-1.2g / ml, and the elongation at break is 50-200%. The polyurethane-material polishing pad and the preparation method have the advantages of simple process, low production cost and manufacturing cost, low energy consumption, short production period, fast degradation speed and environmental-friendly effect.

Description

technical field [0001] The invention relates to the polishing technical field of chemical mechanical planarization treatment, in particular to a polishing pad and a preparation method thereof. Background technique [0002] Chemical mechanical planarization, or chemical mechanical polishing (CMP), is a common technique used to planarize semiconductor wafers, substrates such as sapphire. In conventional CMP, the wafer is mounted on a holder assembly, and the wafer is brought into contact with a polishing pad in the CMP apparatus. The holder assembly provides controlled pressure on the wafer, pressing the wafer against the polishing pad. The applied driving force causes rotational motion of the polishing pad relative to the wafer. At the same time, a chemical composition or other polishing solution is provided between the wafer and the polishing pad. Thereby, the surface of the wafer is polished and flattened by the chemical and mechanical action of the polishing pad surface...

AI Technical Summary

Problems solved by technology

[0004] Polyurethane polishing pads are usually composed of a polishing layer, a buffer layer and a transparent bottom pad. During manufacture, since the polishing layer and the buffer layer are all polyurethane materials, the prepolymer as an important manufacturing raw material is often used in order to ensure that the material can be stored for a long time. High-molecular-weight prepolymers, polyisocyanic acid refers to the high-molecular-weight prepolymers generated after reacting with polyols, which have high viscosity and poor fluidity, so there are the following problems: (1) In order to avoid mixing bubbles in the polishing layer and affecting the polishing effect , so it is necessary to defoam the prepolymer, and due to the high viscosity of the generated prepolymer (viscosity can reach 4000mPa·S, the test temperature is 80°C), the air bubbles mixed in the prepolymerization reaction are not easy to come out, so a higher Energy consumption is used for defoaming. If vacuum defoaming is used, it is necessary to control the vacuum degree to -0.096MPa, the temperature is 100°C, and the time is up to 120 minutes.

[0005] On the other hand, after the polishing pad works for a period of time, its original surface roughness decreases, and the debris from the polishing pad, the debris after the removal of the silicon wafer, and the particles in the polishing liquid will block the small holes and affect the transportation of the polishing liquid. , so that the polishing performance deteriorates or even fails, and new polishing pads need to be replaced continuously

The consumption of polishing pads accounts for about 1 / 3 of the entire CMP consumption cost, and a large number of replacement polishing pads will greatly increase the manufacturing cost and cause serious environmental pollution

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