| Pacific Rim Symposium on Surfaces, Coatings and Interfaces (PacSurf 2014) | |
| Thin Films | Tuesday Sessions |
| Session TF-TuP |
| Session: | Thin Films Poster Session |
| Presenter: | SuMin Hwang, Inha University |
| Authors: | S.M. Hwang, Inha University A. Garay Dixon, Inha University J.H. Choi, Inha University C.W. Chung, Inha University |
| Correspondent: | Click to Email |
In the semiconductor memory device field, for the next generation it is a big challenge to develop a memory device that has fast speed of read and write, high density of memory storage and non-volatility. Nowadays, Magnetic random access memory (MRAM), one of the possible candidates for non-volatile random access memory (NVRAM), has a received great deal of attention due to its several advantages.
Magnetic random access memory (MRAM) is a hybrid technology between a spintronic device and standard silicon-based microelectronics. Compared to commercial memory devices such as DRAM, SRAM and flash memory, based on charge storage, MRAM devices store data by employing the magnetoresistance effect. MRAM consists of a magnetic tunnel junction (MTJ) stack and a complementary metal-oxide semiconductor (CMOS). MTJ stack is an important part of the MRAM and it is composed of various magnetic materials, metals, and a tunneling barrier layer.
The etching of magnetic materials such as NiFe, NiFeCo, CoFe, CoFeB and FePt using halogen containing gas have been widely researched. However, halogen gases chemistries tend to produce non-volatile etch by products that can cause the corrosion of the magnetic materials after etching. Recently, Co2MnSi co-heusler alloy was used as a magnetic material because of high spin polarization and a high Curie temperature (~985K). Furthermore, several researches have reported that the etching of magnetic materials by C, H, O containing gases can produce a vertical etch profile with no post etching redeposition. Therefore, the etch characteristics of Co2MnSi thin films using C, H, O containing gas should be developed.
In this study, the etch characteristics of Co2MnSi thin films have been investigated in CH4/O2/Ar gas mixtures using an inductively coupled plasma reactive ion etching (ICPRIE). TiN thin films were applied as a hard mask to enhance the etch selectivity. The etch rates were obtained using surface profilometer and etch profiles were observed by using the field emission scanning electron microscopy (FESEM). The condition of plasma during process was employed by optical emission spectroscopy (OES).