07/15/2025 | Press release | Distributed by Public on 07/15/2025 20:00
Plasma-enhanced chemical vapor deposition (PECVD) is one of the fundamental building blocks for manufacturing ICs. From building the transistor to metallization, the PECVD process has applications critical for microelectronics manufacturing. PECVD allows to create a desired reactive gas plasma to deposit a thin film on the wafer. Typically, PECVD tools are used in manufacturing most microelectronic devices. For example, PECVD deposits high-quality dielectric films for applications such as lining deep-trench capacitors in DRAM, the multiple oxide-nitride-oxide-nitride (ONON) layers in NAND flash, and other insulating and sacrificial layers throughout the process flow.
PECVD is one of the critical processes for depositing ONON layers needed for 3D NAND. NAND is scaling rapidly, from 232 layers in 2025 to 1,000 layers or more by 2027. Building more layers while keeping the chip at the same size means more memory in the same space or a smaller area. Shrinking the die size helps to drive smaller form factors for devices that use solid-state storage, phones, PCs, consumer devices, and server farms.
Development of 3D DRAM is progressing rapidly, with high-volume manufacturing expected by 2030. Moving to 3D for DRAM provides many of the same storage benefits as 3D NAND: increased density, improved performance, and cost reduction compared to traditional DRAM. Vertical stacking allows for shorter interconnects, leading to faster access times and lower latency, which is critical for artificial intelligence (AI) and other high-performance computing applications. 3D DRAM uses a deep-trench capacitor architecture formed by etching into the silicon substrate a 50:1 to 100:1 trench, which is then lined using PECVD, where film conformality is critical. For both NAND and DRAM, larger memory density on a smaller die can help to reduce energy costs while increasing storage at a lower cost per bit.
Deposition of PECVD films is defined by several key success criteria:
· Uniformity across the wafer to achieve die-to-die electrical performance.
· Process precision to ensure the proper thickness of the stacking and barrier layers.
· Stress control to eliminate warpage and delamination.
· Conformality of the film to prevent pinching of high aspect ratio trenches and cylinders.
· Low defect levels to ensure high yields
ACM Research has developed unique hardware and processes for 3D NAND, including the Ultra Pmax PECVD. The Ultra Pmax manages the continuous deposition of ultra-thin, uniform stacked ONON layers without the need to halt deposition. The combination of managing plasma bias and a special rotating heater provides stress-free 10-15 nm ONON layers in stacks of greater than 100 layers in a single deposition step. This provides ACMR's customers with high wafer-per-hour throughput and excellent process performance.
For trenches and cylinders with a greater than 5:1 aspect ratio, Ultra Pmax PECVD has consistently demonstrated > 40% coverage at the bottom of the trench with excellent uniformity across the wafer. The proprietary Ultra Pmax PECVD system also addresses multiple process applications, including: SiO2, Si3N4, ON/ON, TEOS, APF(C), DARC (SiON), NFDARC (SiOC), NDC (SiCN w/ 4MS), ODC (SiCO), and ACL (C3H6), to name a few.
Additional features differentiate Ultra Pmax PECVD from competitive systems include:
· An optimized layout that can accommodate up to 3 or 5 process modules. Each module handles 3 wafers, so up to 9 or 15 wafers can be processed simultaneously, resulting in high process throughput.
· A dedicated RF power supply and impedance match on each wafer pedestal.
· Automatic shower head tilting and heater leveling optimization
· Wafer rotation in between deposition layers
· A special focus ring for controlling and balancing radial/azimuthal gas flow across the wafer.
Implementing the Ultra Pmax PECVD allows 3D NAND device makers to achieve faster, more uniform deposition while preventing thermal damage to underlying layers, maintaining structural integrity, and optimizing electrical performance via lower-temperature processing. Together, these capabilities enable superior film uniformity and layer precision on even the most challenging processes.
ACMR's patent-pending 300mm Ultra Pmax PECVD is enabling the next generation of logic and memory semiconductors. ACMR's PECVD technology provides superior thin, uniform, and sequential ON/ON stack layer deposition for >232-layer 3D NAND applications. The Ultra Pmax PECVD supports dielectric deposition into features with >5:1 aspect ratio, meeting the needs of applications using deep trenches and cylinders such as 3D DRAM and advanced logic devices.
To learn more about how Ultra Pmax PECVD can help meet the requirements of your 3D memory packaging application, click here.