Endpoint solution for photomask chrome loads down to 0.25%

Buie, Melisa J.; Stoehr, Brigitte C.; Buxbaum, A.; Ruhl, G.

doi:10.1117/12.458342

Cited by 13 publications

(7 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Three endpoint systems were used: a standard monochromator-based optical emission endpoint system, the High Optical Throughput (HOTTM) detectors, and a CCD camera fill-spectrum endpoint system that is capable oftaking full spectrum data at rates greater than 1 Hz. [2] The monochromatorwas used to monitor either single or multiple spectral lines at a given time during the etch. The HOT detector uses a filter that collects signal from a single line.…”

Section: Methodsmentioning

confidence: 99%

<title>Optical emission endpoint optimization in the tetra etch chamber for production of embedded phase-shift photomasks</title>

Brooks

Anderson

et al. 2003

19th European Conference on Mask Technology for Integrated Circuits and Microcomponents

Self Cite

View full text Add to dashboard Cite

The Etec Systems TetraTM photomask etch system is currently used to etch attenuated phase shift photomasks. Currently, MoSiON is a common film used for phase shifting. Either chrome or re sist can be used as a mask for etching this film. Because the quartz substrate etches with the same chemistry commonly used to etch MoSiON, precise endpoint control is necessary to meet the phase targeting requirements to create this type of phase-shifting mask. This paper will address techniques used to obtain precise endpoint control ofthe MoSiON-quartz boundary.Endpoint control is required for the precise phase targeting of 1 800 1 .5° needed for advanced subwavelength patterning technologies. In this paper, optical emission spectroscopy is used to characterize and monitor chrome etch processes on the Etec Systems TetraTM photomask etch chamber. Changes in process conditions have been captured by time-averaged optical emission traces. Using multi-wavelength optical emission spectroscopy data collected during MoSiON etching, a fingerprint ofthe plasma can be taken. The fingerprint is used to detect changes in emission lines during the etch and determine the best wavelength for endpoint detection. Secondly, this paper will examine numerical methods ofendpoint optimization, including averaging, smoothing and derivative techniques.

show abstract

Section: Methodsmentioning

confidence: 99%

<title>Optical emission endpoint optimization in the tetra etch chamber for production of embedded phase-shift photomasks</title>

Brooks

Anderson

et al. 2003

19th European Conference on Mask Technology for Integrated Circuits and Microcomponents

Self Cite

View full text Add to dashboard Cite

show abstract

“…is due to the etch of the ARC layer. The signal is lower during the etch of the ARC layer than in the etch of the metallic Cr layer since the Cr concentration in the ARC layer is lower [2]. After the endpoint is reached (at the crosses in Figure 6) The consistency in the endpoint trace shape is certainly a measure of the consistency in tool performance.…”

Section: Endpoint Timementioning

confidence: 97%

“…Each mask was measured at 25 data points on the masks in a 5 × 5 square pattern as sketched in Figure 4. Each point is 34 mm from adjacent points, providing a whole field of measurement that is (4 × 34 = 136 mm) 2 The etch results with two different chambers at different times over a period of one month are compared. The setup of both tools assumes the ARC (Anti-Reflective Coating) layer of the masks to be 50 nm thick.…”

Section: Measurementmentioning

confidence: 99%

Extended chamber matching and repeatability study for chrome etch

Huang

Buie

Stoehr

et al. 2002

21st Annual BACUS Symposium on Photomask Technology

Self Cite

View full text Add to dashboard Cite

Shrinking design rules, optical proximity correction and advanced phase shifting techniques require new methods of photomask manufacturing. The Applied Materials Centura® photomask etch chamber leverages Applied Materials' extensive etch experience to provide an innovative dry etch solution to the mask dry etch challenges for < 0.13 µm device generations. Repeatable, consistent, stable etch performance is critical for advanced mask manufacturing.An extended chamber matching and repeatability study for chrome etch found that stable chrome and photoresist etch rates (and therefore selectivities) are produced on the Applied Materials Centura photomask etch chamber. The etch responses are consistent mask to mask as well as chamber to chamber. Prior to the extended study, pumping efficiencies, RF source and bias calibrations and optical emission spectral responses were compared. Since the study was performed at several different sites, the metrology tools were calibrated using masks specifically designed for this purpose. The marathon testing illustrates the stable etch performance over time.

show abstract

“…Cr sidewall profile angle dependence on the overetch time was reported. [12] When overetch is too short, the profile angle is too low, mostly due to the footing not removed completely. But the overetch time cannot be set too long because it may introduce other systematic errors such as radial CD distribution.…”

Section: Sidewall Profilesmentioning

confidence: 98%

65-nm node photomask etching with zero CD process bias

Chen

Markovitz

et al. 2005

SPIE Proceedings

View full text Add to dashboard Cite

A robust photomask etching process was studied and developed for 65 nm node photomask production with zero CD process bias. The fabrication process, including pattern generation and transfer do not use data sizing, saving photomask delivery time, improving yield, and reducing fabrication costs. The photomask patterns, without using data sizing cover chrome loads from about 1 percent to 80 percent. For 65 nm critical layer EAPSM, the CD bias of Cr and MoSi etching together is equal to or less than about 20 nm for high and low load photomasks. The etch process and dose adjustment on the 50 keV e-beam writer allow for zero CD process bias, i.e. the data sizing becomes unnecessary in the 65 nm node photomask fabrication. The SMIF pot utilization in both pattern generation and transfer processes significantly improved the defectivity control. Cr and MoSi etch endpoints of 1% load photomasks were clearly detected. Point-to-point CD etch contributions for dark and clear features are 5 nm (3 sigma) or less and final CD value ranges are 8 nm or less. CD etch linearity and other etch properties on SRAF and serif are also discussed. An equation was proposed for calculating phase angle non-uniformity distribution, and phase angle range can be controlled in the range of 1.4 0.3 degree. "Selfmask", i.e. using AR sub-layer as hard mask for beneath chromium sub-layer etch was also discussed.

show abstract

Endpoint solution for photomask chrome loads down to 0.25%

Cited by 13 publications

References 0 publications

<title>Optical emission endpoint optimization in the tetra etch chamber for production of embedded phase-shift photomasks</title>

<title>Optical emission endpoint optimization in the tetra etch chamber for production of embedded phase-shift photomasks</title>

Extended chamber matching and repeatability study for chrome etch

65-nm node photomask etching with zero CD process bias

Contact Info

Product

Resources

About