As manufacturers move to high-volume production for 3D NAND and advanced DRAM, chips must be fabricated quickly with repeatable results for every device on every wafer. For critical conductor etch processes, there are several difficult performance requirements, such as achieving tight critical dimension uniformity for 3D NAND and uniform etch depth for advanced DRAM. Addressing these performance demands while at the same time delivering high productivity is challenging, but as explained in our recent announcement, Lam’s Kiyo F Series conductor etch system meets these combined needs for advanced memory devices.
For 3D NAND and advanced DRAM, Kiyo F Series delivers on-wafer performance with the productivity needed for high-volume manufacturing
FREMONT, CA — (Marketwired) – 05/13/15 – Lam Research Corp. (NASDAQ: LRCX), a major global supplier of innovative wafer fabrication equipment and services to the semiconductor industry, today announced its Kiyo® F Series conductor etch system is enabling the transition of 3D NAND and advanced DRAM into volume production. Key etch requirements for these applications include achieving tight critical dimension (CD) uniformity and control for 3D NAND and uniform etch depth for DRAM. Leveraging proprietary Mixed-Mode Pulsing (MMP) technology, the Kiyo F Series delivers the performance needed for advanced memory applications while maintaining high productivity. As a result, the product has won numerous critical etch market positions for advanced memory and other technology inflections, which is leading to additional market share gains.
“For 3D NAND, our customers face significant challenges in addressing difficult etch requirements, meeting aggressive production ramps, and achieving the cost benefits they need to make the transition from planar NAND,” said Vahid Vahedi, group vice president, Etch Product Group. “We are collaborating closely with them to address these new challenges and to enable this inflection by delivering robust, timely solutions without compromising productivity.”
By stacking memory cells vertically, NAND flash manufacturers can pack more storage capacity onto a smaller device, ease lithography requirements, and reduce manufacturing cost per bit. For multilayer 3D NAND structures, critical conductor etch processes include staircase etch and high aspect ratio (HAR) mask open for vertical channels. This mask open is crucial since it defines the CD and CD uniformity for subsequent etching of the vertical transistor channels. For staircase etch, equal-width “steps” are created at the edge of each dielectric-film pair throughout the 3D stack to form a staircase-shaped structure. Because of extensive repetition of these steps during device processing, etching at high throughput with stringent process control is vital. CD variability must be tightly managed since wordline contacts may otherwise miss landing on a step that is too narrow or uneven. For advanced DRAM devices, depth control is a key parameter, particularly for HAR front-end-of-line silicon etch applications. Concerns include aspect ratio loading, where etch rates vary because of differences in feature dimensions, and depth loading, where different etch depths may occur due to pattern density variations.
Building on Lam’s market-leading Kiyo conductor etch products, the Kiyo F Series delivers high productivity while minimizing variability for advanced memory applications. Lam’s MMP technology provides advanced profile and CD control for vertical profiles with good selectivity and tuning controls for consistent etch depths. These capabilities enable higher trim rate for 3D NAND staircase etch along with excellent repeatability, which is needed for manufacturing environments. Symmetric chamber design and radial tuning provide best-in-class uniformity, which is essential for minimizing CD variability. For new generations of advanced memory as well as logic devices, MMP technology enables atomic layer etching (ALE), providing extendibility and repeatability with atomic-scale fidelity.
Kiyo F Series has won production and development tool of record positions for critical conductor etch applications at all major memory manufacturers. For 3D NAND, applications include staircase etch and HAR mask open for vertical channel and slit; for DRAM, these include HAR gates, HAR trenches, and metal recess. Because of these wins, the Kiyo F Series installed base has more than tripled in the past 12 months. In addition, due to strong positions at technology inflections, the product is expected to gain significant adoption as next-generation processes move into production.