Volatile ALD & amp; CVD magnesium precursors for non-volatile memory and flexible display applications

Volatile ALD & amp; CVD magnesium precursors for non-volatile memory and flexible display applications

The escalating struggle with further scaling of integrated circuit chips, on account of certain feature sizes in advanced chips gradually hitting atomic dimensions, has compelled the semiconductor industry to become more welcoming to new materials as a possible solution to continued PPAC (Power-Performance-Area-Cost) improvement. Traditionally not so popular in the semiconductor industry, Magnesium (Mg) is being explored for use in various related applications due to the fact that it forms semiconductor compounds with oxygen, sulfur, selenium, and tellurium.

For example, Magnesium Oxide (MgO) is a semiconductor with a wide band-gap and semi-insulating properties. A very thin semi-insulating MgO layer between two metallic ferromagnetic layers is used as a “magnetic tunnel junction”. Magnetic tunneling junctions (MTJs) based on the CoFeB/MgO/CoFeB layer have received great attention as a promising candidate for future spin logic devices. Among various applications of MTJs, spin-transfer-torque magnetic random access memory (STT-MRAM) is emerging as a strong candidate as a next-generation nonvolatile memory due to its simple integration scheme, low voltage operation, and high speed. To fulfill certain critical requirements of 3D MTJ based sub-20 nm, high-density STT-MRAM, Samsung Advanced Institute of Technology (SAIT), Korea, has recently investigated both thermal and plasma-enhanced ALD for depositing a MgO tunnel barrier using bis(cyclopentadienyl)magnesium precursor under the scope of the Industrial Strategic Technology Development Program (10041926, Development of high-density plasma technologies for the thin-film deposition of nanoscale semiconductors and flexible-display processing) funded by the Ministry of Knowledge Economy (MKE, Korea). (Link)

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Figure 1. TEM images of (a) Thermal ALD MgO, (b) PE-ALD MgO grown at 300 °C on a CoFeB layer

 Recently, Panasonic Corporation, Japan, together with the National Institute of Material Science, Japan, reported ALD based Magnesium Phosphate (MgPO) thin-films as magnesium-ion conducting solid-state electrolytes that are considered to be promising candidates for future energy storage and conversion devices. The deposition was carried out at lower deposition temperatures, ranging from 125 to 300 °C, using bis(ethylcyclopentadienyl)magnesium. (Link)

Apart from semiconductor and energy storage applications, Mg is also an interesting candidate for astronomical and optical applications. For example, recent NASA missions that make observations in the ultraviolet, such as the Hubble Space Telescope and the Galaxy Evolution Explorer, employed primary mirrors coated with aluminum and further protected by thin films of Magnesium Fluoride (MgF2). Therefore, the Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA, reported ALD of MgF2 using bis(ethylcyclopentadienyl)magnesium supplied by Strem Chemicals, Inc. (Link)

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Figure 2. Photograph of a concave mirror and convex diffraction grating for a next-generation UV instrument prototype coated with electron beam evaporated aluminum and a protective coating of 10 nm ALD MgF2 deposited at 150 °C.

Our product offering includes precursors worldwide for ALD of Mg-based compounds, i.e, bis(ethylcyclopentadienyl)magnesium [Mg(CpEt)2] (catalog number 12-0510). The colorless to pale yellow liquid phase precursor with a density of 0.95 g/cm3 at 20 °C and vapor pressure of 0.0315 Torr is also sold as pre-packed in cylinders:

  • 98-4006: Bis(ethylcyclopentadienyl)magnesium, min. 98%, 12-0510, contained in 50 ml Swagelok® cylinder (96-1070) for CVD/ALD

 

  • 98-4010: Bis(ethylcyclopentadienyl)magnesium, min. 98%, 12-0510, contained in high-temp 50 ml Swagelok® cylinder (96-1071) for CVD/ALD

For more than fifty years, we’ve been manufacturing inorganic and organometallic chemicals which has led us to expand our product offering of MOCVD, CVD and ALD precursors. We are continually adding new products for this dynamic and exciting field. Our product range includes:

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Products Mentioned in this Blog:

12-0510: Bis(ethylcyclopentadienyl)magnesium, min. 98% (114460-02-5)

98-4006: Bis(ethylcyclopentadienyl)magnesium, min. 98%, 12-0510, contained in 50 ml Swagelok® cylinder (96-1070) for CVD/ALD

98-4010: Bis(ethylcyclopentadienyl)magnesium, min. 98%, 12-0510, contained in high-temp 50 ml Swagelok® cylinder (96-1071) for CVD/ALD

 

Related Product Lines & Resources:

CVD & ALD Precursors
Metallocenes, Derivitives and CP
Organometallics for CVD & ALD
MOCVD, CVD & ALD Precursors Booklet
PURATREM™: High Purity Inorganics
CVD/ALD Precurors Contained in Swagelok® Cylinders

 

*This blog had been researched, produced and written by Jonas Sundqvist.  It is reposted from BALD Engineering’s blog on April 17, 2020.  Original blog: https://www.blog.baldengineering.com/2020/04/volatile-ald-cvd-magnesium-precursors.html