Liquid injection ALD of Cp- based precursors for deposition of dielectric materials
Lead Research Organisation:
University of Liverpool
Department Name: School of Engineering
Abstract
The rapid growth of the silicon-based microelectronics industry since the late 1980's has fuelled a demand for greater integrated circuit functionality and improved performance at lower cost. This requires an increased circuit density, which has been achieved by a continual reduction, or scaling , in the dimensions of the field effect transistor (FET). Previously amorphous SiO2 and more recently variants of Si-O-N have been exploited in metal-oxide-semiconductor field effect transistor (MOSFET) technology, due to the stable high quality Si-SiO2 interface achievable, and excellent electrical isolation properties. Shrinking of the transistor feature size in each new 'generation' of devices, has forced the gate dielectric thickness to be reduced, to the nanometre-scale level where direct electron tunnelling effects and high leakage currents present serious obstacles to future device reliability. These 'generations' are commonly described by 'nodes' determined by the half pitch between two CMOS gate contact or first metal level. While 90nm node technologies are in industrial production, 65nm node technologies are in advanced status of industrial development and expected to enter in full production in 2007 at the latest. To move to the 45nm node and beyond, the use of materials with a higher dielectric constant (k) (cf. SiO2 derivatives) allows an equivalent capacitance to be achieved in a physically thicker insulating layer, providing reduced leakage currents. This is a multidisciplinary project with the ultimate objective of developing novel liquid injection atomic layer deposition (ALD) process technologies for the manufacture of next generation gate dielectric thin films. The principal aims of the project are therefore to develop an ALD process based on volatile cyclopentadienyl precursors for deposition of hafnium and rare-earth metal oxides, and to assess the physico-chemical and electronic properties of the resulting high-? dielectric films for semiconductor applications.
Publications
Black K
(2016)
Silver Ink Formulations for Sinter-free Printing of Conductive Films.
in Scientific reports
Zhao CZ
(2011)
Dielectric Relaxation of La-Doped Zirconia Caused by Annealing Ambient.
in Nanoscale research letters
Zhao C
(2013)
Grain size dependence of dielectric relaxation in cerium oxide as high-k layer.
in Nanoscale research letters
Zhao C
(2013)
Dielectric relaxation of high-k oxides.
in Nanoscale research letters
Zhao C
(2014)
Hysteresis in Lanthanide Aluminum Oxides Observed by Fast Pulse CV Measurement.
in Materials (Basel, Switzerland)
Zhao C
(2014)
Review on Non-Volatile Memory with High-k Dielectrics: Flash for Generation Beyond 32 nm.
in Materials (Basel, Switzerland)
Lu Q
(2015)
Electrical Properties and Interfacial Studies of HfxTi1-xO2 High Permittivity Gate Insulators Deposited on Germanium Substrates.
in Materials (Basel, Switzerland)
Taechakumput P
(2012)
Thermal Stability of Neodymium Aluminates High- ? Dielectric Deposited by Liquid Injection MOCVD Using Single-Source Heterometallic Alkoxide Precursors
in Journal of Nanomaterials
Black K
(2008)
Deposition of ZrO2 and HfO2 thin films by liquid injection MOCVD and ALD using ansa-metallocene zirconium and hafnium precursors
in Journal of Materials Chemistry
Kanjolia R
(2011)
Dimethylzinc adduct chemistry revisited: MOCVD of vertically aligned ZnO nanowires using the dimethylzinc 1,4-dioxane adduct
in Journal of Crystal Growth
Description | The main outcomes of this project were the: • Molecular design and synthesis of volatile chemical precursors which are suitable for the liquid injection vapour deposition manufacturing methods, such as CVD and ALD. These precursors include new cyclopentadienyl (Cp) precursors for hafnium, zirconium and a range of lanthanide complexes. • Development of liquid injection deposition processes for the manufacture of high permittivity dielectric (high-k) hafnium and lanthanide oxide thin films. • Electrical characterisation and properties of test MOS capacitors fabricated using hafnium and rare earth oxide films. This approach was sucessfully used to elucidate key performance parameters including the electronic interface state densities, oxide charge levels, leakage currents and dielectric strength. • Assessment of the role of hydrogen during the annealing of high k MOSC's, in the reduction of defects both and the high-k/silicon interface and in the bulk of the high k dielectric film. Overall the project demonstrated that liquid injection provides an alternative to previous manufacturing routes, coupled with the potential for improved precursor utilisation and reduced manufacturing costs. |
Exploitation Route | The outcomes of the project have been exploited in TSB and EU funded industry-led projects working in the sectors of CMOS electronics, architectural glazing and power electronic devices. Several of the precursors developed were patented in conjuction with SAFC Hitech. These precursors are now sold by the company to leading IC manufacturers and research groups worldwide. |
Sectors | Electronics |
Description | Liquid injection has enabled the deposition of a range of dielectric materials, which has been exploited by a number of European IC manufactures for the production memory devices. |
First Year Of Impact | 2009 |
Sector | Electronics,Manufacturing, including Industrial Biotechology |
Impact Types | Societal Economic |
Description | SAFC Hitech |
Organisation | Sigma-Aldrich |
Department | S a F C Hitech |
Country | United Kingdom |
Sector | Private |
Start Year | 2006 |
Title | HIGH-K DIELECTRIC FILMS AND METHODS OF PRODUCING USING CERIUM-BASED ß-DIKETONATE PRECURSORS |
Description | Methods are provided to form and stabilize high-? dielectric films by chemical phase deposition processes using metal-source precursors and cerium-based ß-diketonate precursors according to Formula I: Ce(L)x (Formula I) wherein: L is a ß-diketonate; and x is 3 or 4. Further provided are methods of improving high-? gate property of semiconductor devices by using cerium precursors according to Formula I. High-? dielectric films are also provided comprising hafnium oxide, titanium oxide or mixtures thereof, and further containing a permittivity maintaining or increasing amount of cerium atoms. |
IP Reference | WO2009143456 |
Protection | Patent granted |
Year Protection Granted | 2009 |
Licensed | No |
Title | HIGH-K DIELECTRIC FILMS AND METHODS OF PRODUCING USING CERIUM-BASED PRECURSORS |
Description | Methods are provided to form and stabilize high-? dielectric films by vapor deposition processes using metal-source precursors and cerium-based precursors according to Formula I: Ce(L)x (Formula I) wherin L is a cyclopentadienyl ring optionally substituted with one or more substituents independently selected from the group consisting of alkyl, alkoxy and NR1R2; or L is alkoxy; R1 and R2 are independently hydrogen or alkyl; and x is 3 or 4. Further provided are methods of improving high-? gate property of semiconductor devices by using cerium precursors according to Formula I. High-? dielectric film-forming lattices are also provided comprising cerium precursors according to Formula I. |
IP Reference | WO2009143452 |
Protection | Patent granted |
Year Protection Granted | 2009 |
Licensed | No |
Title | HIGH-K DIELECTRIC FILMS AND METHODS OF PRODUCING USING TITANIUM-BASED ß-DIKETONATE PRECURSORS |
Description | Methods are provided to form and stabilize high-? dielectric films by vapor deposition processes using metal-source precursors and titanium-based ß-diketonate precursors according to Formula I: Ti(L)x wherein: L is a ß-diketonate; and x is 3 or 4. Further provided are methods of improving high-? gate property of semiconductor devices by using titanium precursors according to Formula I. High-? dielectric film-forming lattices are also provided comprising titanium precursors according to Formula I. |
IP Reference | WO2009143460 |
Protection | Patent granted |
Year Protection Granted | 2009 |
Licensed | No |
Title | HIGH-K DIELECTRIC FILMS AND METHODS OF PRODUCING USING TITANIUM-BASED PRECURSORS |
Description | Methods are provided to form and stabilize high-? dielectric films by vapor deposition processes using metal-source precursors and titanium-based precursors corresponding in structure to Formula I wherin L is a cyclopentadienyl ring optionally substituted with one or more substituents independently selected from the group consisting of alkyl, alkoxy and NR1R2; or L is alkoxy; R1 and R2 are independently hydrogen or alkyl; and x is 3 or 4. Further provided are methods of improving high-? gate property of semiconductor devices by using titanium precursors according to Formula I. High-? dielectric film-forming lattices are also provided comprising titanium precursors according to Formula I. |
IP Reference | WO2009143458 |
Protection | Patent granted |
Year Protection Granted | 2009 |
Licensed | No |