The Nanoscale AFM-CD standard (CD, critical dimension) contains patterns on the nanometer scale for the linewidth and also the pitch calibration of scanning probe microscopy methods (atomic force microscopy (AFM)).
The Nanoscale AFM-CD-standard offers a series of very smooth and sharp-edged line-space structures in silicon with vertical side-walls. The smallest lines are around 50 nm wide, 250 nm deep and extremely parallel with deviations of below 10 nm.
Each calibration chip has a size of 8×8 mm². In the centre of the calibration chip, where the two-stage finding structure ends, 6 groups of 5 line-space structures with different nominal widths (50, 100, 150, 200, 300 and 800 nm) are arranged.
The space between the lines is about 1 μm. Each group is nominally 10 μm long. The structures are sharp-edged with edge radii of less than 15 nm. The edge roughness is well below 5 nm (3σ).
|Substrate||Material: <110> Si|
Chip dimension: 8×8 mm²
Surface roughness: <1 nm
|Finding structures||Grooves in the Si-substrate|
Depth: 250 nm
|Types of grating||1-dim
|Size of grating||Normally 10×10 µm²
|Linewidths (CD)||Nominal: 50 nm, 100 nm, 150 nm, 200 nm, 300 nm, 800 nm|
Linewidth variation along the lines (measured within a central part of about 1 µm):<3 nm 1σ
|Pitches|| 1 µm + CD value|
Uncertainty of mean pitch: 3 nm 1 σ
|Structure depth||250 nm
|Edge radius||<15 nm
|Edge roughness||<5 nm (p-p)
|Traceability||CD & pitch-calibration made by the PTB Braunschweig on request.|
Chip and pattern description
SEM micrographs (Zeiss Supra 35 VP)
An der Lehmgrube 11