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- Ahvenniemi, Esko, et al.
(författare)
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Recommended reading list of early publications on atomic layer deposition-Outcome of the "Virtual Project on the History of ALD"
- 2017
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Ingår i: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films. - : American Vacuum Society. - 0734-2101 .- 1520-8559. ; 35:1
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Forskningsöversikt (refereegranskat)abstract
- Atomic layer deposition (ALD), a gas-phase thin film deposition technique based on repeated, self-terminating gas-solid reactions, has become the method of choice in semiconductor manufacturing and many other technological areas for depositing thin conformal inorganic material layers for various applications. ALD has been discovered and developed independently, at least twice, under different names: atomic layer epitaxy (ALE) and molecular layering. ALE, dating back to 1974 in Finland, has been commonly known as the origin of ALD, while work done since the 1960s in the Soviet Union under the name "molecular layering" (and sometimes other names) has remained much less known. The virtual project on the history of ALD (VPHA) is a volunteer-based effort with open participation, set up to make the early days of ALD more transparent. In VPHA, started in July 2013, the target is to list, read and comment on all early ALD academic and patent literature up to 1986. VPHA has resulted in two essays and several presentations at international conferences. This paper, based on a poster presentation at the 16th International Conference on Atomic Layer Deposition in Dublin, Ireland, 2016, presents a recommended reading list of early ALD publications, created collectively by the VPHA participants through voting. The list contains 22 publications from Finland, Japan, Soviet Union, United Kingdom, and United States. Up to now, a balanced overview regarding the early history of ALD has been missing; the current list is an attempt to remedy this deficiency.
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| 2. |
- Forsberg, Markus, 1970-
(författare)
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Chemical Mechanical Polishing of Silicon and Silicon Dioxide in Front End Processing
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Chemical mechanical polishing (CMP) has been used for a long time in the manufacturing of prime silicon wafers for the IC industry. Lately, other substrates, such as silicon-on-insulator has become in use which requires a greater control of the silicon CMP process. CMP is used to planarize oxide interlevel dielectric and to remove excessive tungsten after plug filling in the Al interconnection technology. In Cu interconnection technology, the plugs and wiring are filled in one step and excessive Cu is removed by CMP. In front end processing, CMP is used to realize shallow trench isolation (STI), to planarize trench capacitors in dynamic random access memories (DRAM) and in novel gate concepts. This thesis is focused on CMP for front end processing, which is the processing on the device level and the starting material. The effects of dopants, crystal orientation and process parameters on silicon removal rate are investigated. CMP and silicon wafer bonding is investigated. Also, plasma assisted wafer bonding to form InP MOS structures is investigated. A complexity of using STI in bipolar and BiCMOS processes is the integration of STI with deep trench isolation (DTI). A process module to realize STI/DTI, which introduces a poly CMP step to planarize the deep trench filling, is presented. Another investigated front end application is to remove the overgrowth in selectively epitaxially grown collector for a SiGe heterojunction bipolar transistor. CMP is also investigated for rounding, which could be beneficial for stress reduction or to create microoptical devices, using a pad softer than pads used for planarization. An issue in CMP for planarization is glazing of the pad, which results in a decrease in removal rate. To retain a stable removal rate, the pad needs to be conditioned. This thesis introduces a geometrically defined abrasive surface for pad conditioning.
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