Post-Sputtering Heat Treatments of Molybdenum on Silicon Wafer

Xuguang Jia,Gavin Conibeer,Terry Chien-Jen Yang,Ivan Perez-Wurfl,Lingfeng Wu,Binesh Puthen-Veettil,Ziyun Lin

doi:10.3390/app8091692

Abstract

This paper investigated the property evolutions of Mo thin films that were subjected to post-sputtering heat treatments from 700 °C to 1100 °C. It was found that, after annealing, the use of Si wafers eliminated crack formations found in previously reported Mo thin films sputtered on fused silica substrates. The recrystallization of the Mo thin film was found to start at 900 °C, which led to rearrangements of the preferred crystalline orientation and enhancement of grain size when the annealing temperature was further increased. The electrical conductivity of the Mo thin films was majorly affected by the increase of Mo crystallite size as the annealing temperature was increased. Overall, the improvement of material sustainability and compatibility in the high temperature annealing process has made it positive to implement a Mo-Si contact-substrate scheme for vertical structured Si QDs solar cells.

Highlights

Structured Si quantum dot (QDs) solar cells implementing a Molybdenum (Mo) back contact layer have been proposed as a method to overcome the current crowding effects found in previous mesa-structured cells [1,2,3,4]
The deposition of Mo thin film was was done in an AJA sputtering system, with a direct current (DC) power of 160 W supplied to done in an AJA sputtering system, with a direct current (DC) power of 160 W supplied to the target
This paper studied the properties of Mo thin films sputtered on Si wafer substrates, which were

Summary

Introduction

Structured Si quantum dot (QDs) solar cells implementing a Molybdenum (Mo) back contact layer have been proposed as a method to overcome the current crowding effects found in previous mesa-structured cells [1,2,3,4]. This requires employment of a conductive interlayer between the Si QDs solar cell, and the substrate to serve as the back contact. Apart from the expected improvement in current output, another benefit of the vertical structure is that it simplifies the fabrication process by removing the necessity of reactive ion etching (RIE) to create mesa-islands as previously needed

Methods

Results

Conclusion