Mr. Takafumi Morimoto Profile

Takafumi Morimoto

Engineer at Hitachi Kenki FineTech Co Ltd

SPIE Involvement:

Author

Publications (8)

SPIE Journal Paper | 12 March 2012

Atomic force microscope method for sidewall measurement through carbon nanotube probe deformation correction

Masahiro Watanabe, Shuichi Baba, Toshihiko Nakata, Takafumi Morimoto, Satoshi Sekino, Hiroshi Itoh

JM3, Vol. 11, Issue 1, 011009, (March 2012) https://doi.org/10.1117/12.10.1117/1.JMM.11.1.011009

KEYWORDS: Atomic force microscope, Carbon nanotubes, Atomic force microscopy, Silicon, Calibration, Cadmium, Sensors, Signal detection, Eye, Distortion

Read Abstract +

Proceedings Article | 24 March 2009 Paper

AFM method for sidewall measurement through CNT probe deformation correction and its accuracy evaluation

Masahiro Watanabe, Shuichi Baba, Toshihiko Nakata, Hiroshi Itoh, Takafumi Morimoto, Satoshi Sekino

Proceedings Volume 7272, 72721P (2009) https://doi.org/10.1117/12.813375

KEYWORDS: Deconvolution, Atomic force microscopy, Critical dimension metrology, Signal detection, Cerium, Sensors, Silicon, Eye, Calibration, Distortion

Read Abstract +

To use atomic force microscope (AFM) to measure dense patterns of 32-nm node structures, there is a difficulty in providing flared probes that go into narrow vertical features. Using carbon nanotube (CNT) probes is a possible alternative. However, even with its extremely high stiffness, van der Waals attractive force from steep sidewalls bends CNT probes. This probe deflection effect causes deformation (or "swelling") of the measured profile. When measuring 100-nm-high vertical sidewalls with a 24-nm-diameter and 220-nm-long CNT probe, the probe deflection can cause a bottom CD bias of 13.5 nm. This phenomenon is inevitable when using long, thin probes whichever scanning method is used. We proposed a method to deconvolve this probe deflection effect. By detecting torsional motion of the base cantilever for the CNT probe, it is possible to estimate the amount of CNT probe deflection. Using this information, we have developed a technique for deconvolving the probe deformation effect from measured profiles. This technique, in combination with deconvolution of the probe shape effect, enables vertical sidewall profile measurement. We have quantitatively evaluated the performance of the proposed method using an improved version of a "tip characterizers" developed at the National Institute of Advanced Industrial Science and Technology (AIST), which has a well-defined high-aspect-ratio line and space structure with a variety of widths ranging from 10 to 60 nm. The critical dimension (CD) values of the line features measured with the proposed AFM method showed good matches to TEMcalibrated CD values. The biases were within a range of ±1.7 nm for combinations of three different probes, five different patterns, and two different threshold heights, which is a remarkable improvement from the bias range of ±4.7 nm with the conventional probe tip shape deconvolution method. The static repeatability was 0.54 nm (3σ), compared to 1.1 nm with the conventional method. Using a 330-nm-deep tip characterizer, we also proved that a 36-nm-narrow groove could be clearly imaged.

Proceedings Article | 3 April 2008 Paper

Dimension controlled CNT probe of AFM metrology tool for 45-nm node and beyond

Satoshi Sekino, Takafumi Morimoto, Toru Kurenuma, Motoyuki Hirooka, Hiroki Tanaka

Proceedings Volume 6922, 69220L (2008) https://doi.org/10.1117/12.772433

KEYWORDS: Scanning electron microscopy, Metrology, Deconvolution, Transmission electron microscopy, Manufacturing, Atomic force microscopy, Inspection, Photomicroscopy, Semiconductor manufacturing, Error analysis

Read Abstract +

Atomic Force Microscope (AFM) is a powerful metrology tool for process monitoring of semiconductor manufacturing because of its non-destructive, high resolution, three-dimensional measurement ability. In order to utilize AFM for process monitoring, long-term measurement accuracy and repeatability are required even under the condition that probe is replaced. For the measurement of the semiconductor's minute structure at the 45-nm node and beyond, AFM must be equipped with a special probe tip with smaller diameter, higher aspect ratio, sufficient stiffness and durability. Carbon nanotube (CNT) has come to be used as AFM probe tip because of its cylindrical shape with small diameter, extremely high stiffness and flexibility. It is said that measured profiles by an AFM is the convolutions of sample geometry and probe tip dimension. However, in the measurement of fine high-aspect-ratio LSI samples using CNT probe tip, horizontal measurement error caused by attractive force from the steep sidewall is quite serious. Fine and long CNT tip can be easily bent by these forces even with its high stiffness. The horizontal measurement error is caused by observable cantilever torsion and unobservable tip bending. It is extremely difficult to estimate the error caused by tip bending because the stiffness of CNT tips greatly varies only by the difference of a few nanometers in diameter. Consequently, in order to obtain actual sample geometry by deconvolution, it is essential to control the dimension of CNT tips. Tip-end shape also has to be controlled for precise profile measurement. We examined the method for the measurement of CNT probe tip-diameter with high accuracy and developed the screening technique to obtain probes with symmetric tip-ends. By using well-controlled CNT probe and our original AFM scanning method called as Advanced StepIn^TM mode, reproducible AFM profiles and deconvolution results were obtained. Advanced StepIn^TM mode with the dimension- and shape-controlled CNT probe can be the solution for process monitoring of semiconductor manufacturing at the 45-nm node and beyond.

Proceedings Article | 22 March 2008 Paper

A novel AFM method for sidewall measurement of high-aspect ratio patterns

Masahiro Watanabe, Shuichi Baba, Toshihiko Nakata, Takafumi Morimoto, Satoshi Sekino

Proceedings Volume 6922, 69220J (2008) https://doi.org/10.1117/12.772712

KEYWORDS: Atomic force microscopy, Deconvolution, Scanning transmission electron microscopy, Silicon, Signal detection, Cerium, Sensors, Distortion, Carbon nanotubes, Calibration

Read Abstract +

Proceedings Article | 5 April 2007 Paper

New inline AFM metrology tool suited for LSI manufacturing at the 45-nm node and beyond

Manabu Edamura, Yuichi Kunitomo, Takafumi Morimoto, Satoshi Sekino, Toru Kurenuma, Yukio Kembo, Masahiro Watanabe, Shuichi Baba, Kishio Hidaka

Proceedings Volume 6518, 65183M (2007) https://doi.org/10.1117/12.711676

KEYWORDS: Atomic force microscopy, Semiconducting wafers, Metrology, Photoresist materials, Manufacturing, Carbon nanotubes, Chemical mechanical planarization, Sensors, Scanners, Very large scale integration

Read Abstract +

Proceedings Article | 2 June 2003 Paper

New atomic force microscope method for critical dimension metrology

Takafumi Morimoto, Toru Shinaki, Yukio Kembo, Sumio Hosaka

Proceedings Volume 5038, (2003) https://doi.org/10.1117/12.482813

KEYWORDS: Silicon, Atomic force microscopy, Atomic force microscope, Critical dimension metrology, Silicon carbide, Metrology, Carbon, Scanning electron microscopy, Carbon nanotubes, Semiconductors

Read Abstract +

SPIE Journal Paper | 1 January 2003

New atomic force microscopy imaging for an inline large scale integration process monitor

Sumio Hosaka, Takafumi Morimoto, Hiroshi Kuroda, Yasushi Minomoto, Yukio Kembo, Hirokazu Koyabu

JM3, Vol. 2, Issue 01, (January 2003) https://doi.org/10.1117/12.10.1117/1.1530572

KEYWORDS: Atomic force microscopy, Servomechanisms, Semiconducting wafers, Control systems, Error analysis, Photoresist materials, Imaging systems, Scanning electron microscopy, Silicon, Image processing

Read Abstract +

Proceedings Article | 16 July 2002 Paper

New AFM imaging for an in-line LSI process monitor

Sumio Hosaka, Takafumi Morimoto, Hiroshi Kuroda, Yasushi Minomoto, Yukio Kembo, Hirokazu Koyabu

Proceedings Volume 4689, (2002) https://doi.org/10.1117/12.473488

KEYWORDS: Atomic force microscopy, Servomechanisms, Semiconducting wafers, Control systems, Error analysis, Argon, Photoresist materials, Silicon, Statistical analysis, Phase shifts

Read Abstract +

Showing 5 of 8 publications

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Keywords/Phrases

Search In:

Publication Years