Abrasive for Chemical Mechanical Polishing

Abstract

Chemical mechanical polishing (CMP) is one of the most essential processes in semiconductor manufacturing. Its importance becomes highly underscored at the advanced device toward sub 14 nm scaling. The fundamental mechanism of CMP is to create soften surface layer by chemical reaction and then, mechanical force by abrasive particles remove soften layer. The role of CMP is not only material removal, but also planarization, surface smoothening, uniformity control, defect reduction and more. Moreover, semiconductor yield enhancement is sensitively influenced by CMP processing. Surface scratching, which is generated by CMP in nature, is considered as 'killer defect' in semiconductor manufacturing. Hence, to achieve proper CMP performance without surface scratching, understanding and development of abrasive particles are crucially important. In this chapter, CMP fundamentals, applications and challenges associated with abrasive particle technology including synthesis (up to nanoparticle scale), tribochemical reaction, abrasive surface zeta potential behavior, particle size and its distribution will be discussed.

Silicon-Based Micromachining Process for Flexible Electronics

“…A CMP process could be significantly influenced by many factors such as abrasives, pH, and polishing temperature [21]. The schema of CMP tool and process to polish wafer are shown in Figure 5 [22]. A wafer is firstly held by the polishing head using a vacuum and then the polishing head starts to rotate, resulting in the rotation of held wafer on the polishing pad [22].…”

“…The schema of CMP tool and process to polish wafer are shown in Figure 5 [22]. A wafer is firstly held by the polishing head using a vacuum and then the polishing head starts to rotate, resulting in the rotation of held wafer on the polishing pad [22]. The slurry used in the CMP process is dispensed through a slurry arm with the help of polishing pad conditioner, and the polishing pad surface is refreshed for each polishing process so that global planarization and polishing can be achieved [22].…”

“…A wafer is firstly held by the polishing head using a vacuum and then the polishing head starts to rotate, resulting in the rotation of held wafer on the polishing pad [22]. The slurry used in the CMP process is dispensed through a slurry arm with the help of polishing pad conditioner, and the polishing pad surface is refreshed for each polishing process so that global planarization and polishing can be achieved [22]. During CMP process, the wafer is polished through abrasive and chemistry, and the complicate interaction between pad asperity, slurry, and wafer surface is described in Figure 5 in a microscale observation [22].…”

“…HF etchant is used to remove BOX Figure 5. The schema of conventional CMP process [22]. Copyright (2018) with permission from IntechOpen.…”

A review on chemical and mechanical phenomena at the wafer interface during chemical mechanical planarization

“…Typical slurry components for dielectric and metal CMP processes are summarized in Table 1. Slurry formulations not only are different depending on the materials to be polished but also need to be optimized to meet the stringent process requirements [7,8]. Their characteristics dominate the various interactions that occur at the slurry/pad-wafer interface.…”