Properties and mechanism of amorphous lead aluminosilicate passivation layers used in semiconductor devices through molecular dynamic simulation. Issue 21 (1st November 2022)

• Record Type: Journal Article
• Authors: Zhong, Cong; Li, Ao; Yan, Jingtao; Jiang, Qi; Yang, Rui; Lu, Kejun; Zeng, Huidan
• Is Part Of: Ceramics international. Volume 48:Issue 21(2022)
• Page Start: 32455
• Page End: 32463
• Publication Date: 2022-11-01
• Subjects: Lead aluminosilicate glasses -- Thermal expansion properties -- MOS structure -- Interface passivation; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2022.07.191
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: With the rapid development of the semiconductor industry, the glass passivation process is being optimized as an important process for the protection of electronic components. Lead aluminosilicate glasses, with a stable network structure, adjustable thermal expansion coefficient and high voltage resistance, are valuable for use in power devices such as diodes. In this work, the effects of PbO content on the expansion and thermal properties of lead aluminosilicate glasses were investigated by combining molecular dynamics simulations and experimental tests. The relationship between structural changes and performance is analyzed in detail, and the passivation mechanism of lead aluminosilicate glass for semiconductor devices is also elucidated. The results show that the thermal expansion coefficients of glass and silica wafers can match the glass composition with PbO contents of 15–25 mol%. The diffusion ability of Pb atoms in the network structure is also the lowest in this concentration range. The glass transition temperature (Tg ) and fluidity at high temperature, both decrease with increasing PbO content. In addition, the glass powder was applied to MOS devices for electrical performance testing. It was found that when the PbO content was at 20 mol%, the glass passivation layer and the silicon wafer had tight interfacial contact after sintering. The interfacial defect density reached the minimum value (5.276 × 10 10 cm −2 eV −1 ) along with a high fixed charge density (2.124 × 10 10 cm −2 ). In other words, the glass powder composed of 20PbO-4.8Al2 O3 -75.2SiO2 (mol%) can minimize the interfacial carrier compound, reduce the interfacial contact resistance and increase the current density to achieve a more desirable interfacial passivation effect in semiconductor devices.