KLA’s new Axion® The T2000 metrology system makes use of the ability of X-rays to measure the advanced vertical constructions that make up superior reminiscence chips.
With a wavelength a lot shorter than seen gentle, X-rays can penetrate objects with little absorption, permitting them to “see” into visually opaque or very thick objects with out damaging them. These properties make X-rays helpful for on a regular basis functions, comparable to medical prognosis and airport safety checks.
Similarly, X-rays are used for metrology functions in chip manufacturing the place it has turn out to be essential to “see” into vertical reminiscence system architectures. Chipmakers are leveraging vertical scaling improvements to realize reminiscence chip efficiency enhancements, quite than relying solely on flat scaling. For instance, 3D NAND reminiscence chips have gotten greater and greater with every new technology – stacking cells to unbelievable heights to realize improved chip efficiency inside a compact system.
The fabrication of those vertical reminiscence chips includes the formation of excessive side ratio (HAR) constructions. These are nanoscale architectural options which are very lengthy and really slim. For instance, channel holes are fashioned by etching holes with a diameter of ~65-100 nm into a movie stack that’s over 10 µm in peak and grows bigger – leading to a side ratio of ≥100:1. These HAR constructions needs to be fashioned with a close to good vertical molding profile, uniform from the highest of the construction to the underside.
To perceive if these vertical constructions are fashioned appropriately, reminiscence producers must measure them exactly throughout your complete peak, which is the place X-rays are available. X-rays move by the reminiscence system and acquire high-resolution form data alongside your complete vertical dimension of the HAR constructions. This is finished with out damaging the reminiscence chip at a velocity quick sufficient for inline monitoring of a number of course of steps throughout excessive quantity manufacturing.
A Novel Answer For X-ray Metrology
The Axion T2000 is a singular X-ray metrology answer for vertical reminiscence chip manufacturing that makes use of CD-SAXS (vital dimension small angle X-ray scattering) expertise. As proven within the animation beneath, a excessive flux supply produces X-rays that move by customized optics and are then emitted by the wafer, which is mounted vertically in a stage. The X-rays work together with the reminiscence system constructions on the wafer, creating diffraction patterns which are imaged by a high-efficiency detector. The platform, with an industry-leading dynamic vary, exactly rotates the wafer in order that the X-rays move at totally different angles of incidence and azimuths. The ensuing set of diffraction pictures is encoded with 3D geometric data. KLA’s industry-leading AcuShape® modeling software program extracts advanced form profile data from these pictures, together with the refined form variations that may have an effect on the performance or efficiency of the reminiscence chip.
With its x-ray imaginative and prescient, the Axion T2000 supplies nondestructive, vital dimensions and high-resolution 3D form measurements, lowering the cycle time required to establish essentially the most difficult form variations in vertical reminiscence chips. Examples of structural variations measured by the Axion T2000 embody 3D NAND channel-hole etch form, tilt, bending, and multi-layer overlay; and hole profile, bending and tungsten cavities. The information produced by Axion is utilized by reminiscence producers in any respect levels of the manufacturing course of. During the day R&D, the Axion T2000 is used to realize quick studying cycles, lowering reliance on lengthy lead time, harmful measurement strategies comparable to FIB-SEM, TEM and cross-sectional SEM. It hurries up driveway cycle time by serving to course of engineers precisely characterize new processes, design nodes and units. During the day excessive quantity manufacturingthe Axion T2000 displays key course of steps inline to make sure that variations affecting reminiscence chip high quality are recognized and rapidly addressed.
For extra data on KLA’s Axion T2000 X-ray metrology system, click on on the product factsheet (left) or go to the Axion product merchandise on KLA’s web site.