Substrate Effect on Plasma Clean Efficiency in Plasma Enhanced Chemical Vapor Deposition System

Shiu-Ko Jangjian,Ying-Lang Wang

doi:10.1155/2007/15754

Abstract

The plasma clean in a plasma-enhanced chemical vapor deposition (PECVD) system plays an important role to ensure the same chamber condition after numerous film depositions. The periodic and applicable plasma clean in deposition chamber also increases wafer yield due to less defect produced during the deposition process. In this study, the plasma clean rate (PCR) of silicon oxide is investigated after the silicon nitride deposited on Cu and silicon oxide substrates by remote plasma system (RPS), respectively. The experimental results show that the PCR drastically decreases with Cu substrate compared to that with silicon oxide substrate after numerous silicon nitride depositions. To understand the substrate effect on PCR, the surface element analysis and bonding configuration are executed by X-ray photoelectron spectroscopy (XPS). The high resolution inductively coupled plasma mass spectrometer (HR-ICP-MS) is used to analyze microelement of metal ions on the surface of shower head in the PECVD chamber. According to Cu substrate, the results show that micro Cu ion and theCuOxbonding can be detected on the surface of shower head. The Cu ion contamination might grab the fluorine radicals produced byNF3ddissociation in the RPS and that induces the drastic decrease on PCR.

Highlights

In semiconductor manufacturing, the nitrogen trifluoride (NF3) is widely used for plasma-enhanced chemical vapor deposition (PECVD) chamber cleaning due to its almost 100% dissociation in a discharge [1]
In order to compare the substrate effect on the plasma clean rate (PCR), the Cu and silicon oxide substrates are simultaneously performed at chamber A and chamber B in PRODUCER SE 300 mm twin PECVD deposition system
The results suggest that the shower head might be contaminated and damaged by Cu ions by using Cu substrate

Summary

INTRODUCTION

The nitrogen trifluoride (NF3) is widely used for plasma-enhanced chemical vapor deposition (PECVD) chamber cleaning due to its almost 100% dissociation in a discharge [1]. In PECVD system, the chemical precursors are excited by plasma to produce dielectric or metallic thin films on silicon wafers. Deposition occurs on the wafer, and on the exposed internal surfaces of the deposition chamber. This residue needs to be removed in order to minimize potential yield loss due to particle contamination and to maintain process integrity. Few reports are demonstrated on the substrate effect of the plasma clean efficiency, especially on the long term performance of the reacted chamber condition in semiconductor manufacturing. The PCR efficiency in PECVD reactor has been studied on Cu and dielectric insulator substrates, respectively. The mechanisms for PCR deviation between the two substrates are proposed and discussed

EXPERIMENT

RESULTS AND DISCUSSION

CONCLUSION