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High-Productivity Combinatorial PVD and ALD Workflows for Semiconductor Logic & Memory Applications

Published online by Cambridge University Press:  31 January 2011

Imran Hashim
Affiliation:
ihashim@intermolecular.com, Intermolecular, 2865 Zanker Road, San Jose, California, 95134, United States, 408-416-2268, 408-416-2301
Chi-I Lang
Affiliation:
clang@intermolecular.com, Intermolecular, San Jose, California, United States
Hanhong Chen
Affiliation:
hchen@intermolecular.com, Intermolecular, San Jose, California, United States
Jinhong Tong
Affiliation:
jinhong@intermolecular.com, Intermolecular, San Jose, California, United States
Monica Mathur
Affiliation:
mmathur@intermolecular.com, Intermolecular, San Jose, California, United States
Prashant Phatak
Affiliation:
pphatak@intermolecular.com, Intermolecular, San Jose, California, United States
Ronald Kuse
Affiliation:
rkuse@intermolecular.com, Intermolecular, San Jose, California, United States
Sandra Malhotra
Affiliation:
sandra@intermolecular.com, Intermolecular, San Jose, California, United States
Sunil Shanker
Affiliation:
sshanker@intermolecular.com, Intermolecular, San Jose, California, United States
Xiangxin Rui
Affiliation:
xrui@intermolecular.com, Intermolecular, San Jose, California, United States
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Abstract

With materials innovation driving recent logic and memory scaling in the semiconductor industry, High-Productivity Combinatorial™ (HPC) technology can be a powerful tool for finding optimum materials solutions in a cost-effective and efficient manner. This paper will review unique HPC wet processing, physical vapor deposition (PVD), and atomic layer deposition (ALD) capabilities that were developed, enabling site-isolated testing of multiple conditions on a single 300mm wafer. These capabilities were utilized for exploration of new chalcogenide alloys for phase change memory, and for metal gate and high-K dielectric development for high-performance logic. Using an HPC PVD chamber, a workflow was developed in which up to 40 different precisely controlled GeSbTe alloy compositions can be deposited in discrete site-isolated areas on a single 300mm wafer and tested for electrical & material properties, using a custom in-situ high-throughput sheet-resistance measurement setup, to get very accurate measurements of the amorphous – crystalline transition temperature. We will review how resistivity as a function of temperature, crystallization temperature, final and intermediate (if any) crystalline phases were mapped for a section of the GeSbTe phase diagram, using only a few wafers. Another area where HPC can be very valuable is for finding optimum materials for high-k dielectrics and metal gates for high-performance logic transistors. Assessing the effective work-function (EWF) for a given high-k dielectric metal-gate stack for PFET and NFET transistors is a critical step for selecting the right materials before further integration. One way to obtain EWF is by using a terraced oxide wafer with different SiO2 thickness bands underneath the high-k dielectric. We report a HPC workflow using our wet, ALD & PVD capabilities, to quickly assess EWF for multiple different high-k dielectrics and metal gate stacks. This workflow starts with a HPC wet etch of thermal silicon oxide, creating different oxide thicknesses 1–10nm in select areas of the same substrate. This is followed by atomic layer deposition of a high-k dielectric film such as HfO2. Next, a metal e.g., TaN is deposited through a physical mask or patterned post-deposition to complete the formation of MOS capacitors. The final step is C-V measurements and C-V modeling to extract Vfb, high-k dielectric constant, EOT, and EWF from Vfb vs EOT plot. This workflow was used to extract EWF for a TaN metal gate with an ALD HfO2 high-k dielectric using a metal-organic precursor. We will discuss how EWF for this system was affected by annealing post-dielectric deposition & post-metallization, different annealing temperatures & ambients, Hf pre-cursors and interfacial cap layers e.g., La2O3 & Al2O3. Finally, we will also discuss more advanced versions of this workflow where the ALD high-k dielectric and PVD metal gate is also varied on the same wafer using HPC versions of ALD & PVD chambers.

Type
Research Article
Copyright
Copyright © Materials Research Society 2009

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References

1 Patton, G., “Semiconductor and System Technology: A Future of Consolidation, Integration, and Discontinuities,” Industry Strategy Symposium, (2009).Google Scholar
2 Johnston, S., “Technology Drivers for the Future: Growth Through Innovation and Excellence,” Industry Strategy Symposium, (2009).Google Scholar
3 Kim, K., “Technology for sub-50nm DRAM and NAND Flash Manufacturing,” Tech. Digest, Int. Electron Devices Meeting, (2005).Google Scholar
4 Srivasta, A., Zhang, P., Kalyanker, N., Karumcheti, A., Fresco, Z., “Accelerating Semiconductor R”, Solid State Technology, October 2007.Google Scholar
5 Wuttig, M. and Yamada, Noboru, “Phase-change materials for rewriteable data storage”, Nature Materials, Vol. 6, pp. 824832, 2007.Google Scholar
6 Lai, S. and Lowery, T., “A chalcogenide-based device with potential for multi-state storage”, TecDigest, h., Int. Electron Devices Meeting, p. 803, 2001.Google Scholar
7 Lee, J.I. et al., “Highly Scalable Phase Change Memory with CVD GeSbTe for Sub 50nm Generation”, VLSI Tech. Digest, p.102, 2007.Google Scholar
8 Lee, M. J. et al., “2-stack 1D-1R Cross-point Structure with Oxide Diodes as Switching Elements for High Density Resistance RAM Applications”, Tech. Digest, Int Electron Devices Meeting, p. 771, 2007.Google Scholar
9 Mistry, K et al., “A 45nm Logic Technology with High-k+Metal Gate Transistors, Strained Silicon, 9 Cu Interconnect Layers, 193nm Dry Patterning, and 100% Pb-free Packaging”, Tech. Digest, Int. Electron Devices Meeting, p.247, 2007.Google Scholar
10 Wen, H.-C. et al., “Comparison of Effective Work Function Extraction Methods Using Capacitance and Current Measurement Techniques”, IEEE Elect. Device Lett., Vol. 27, pp. 598601, 2006.Google Scholar
11 Yang, N., Henson, W., Hauser, J., Wortman, J., “Modeling study of ultrathin gate oxides using direct tunneling and capacitance”, IEEE Trans. Electron Dev. 47 11, pp. 21612166, 2000.Google Scholar
12 Choi, K., et al., “Effective work function modification of atomic-layer-deposited-TaN film by capping layer”, Appl. Phys. Lett., Vol. 89, 032113, 2006.Google Scholar
13 Narayanan, V. et al., “Band-edge high-performance high-k/metal gate n-MOSFETs using cap layers containing group IIA and IIIB elements with gate-first processing for 45nm and beyond”, VLSI Symp. Tech. Digest, pp. 224225, 2006.Google Scholar