Electron Beam Writer Mask System F5112+VD01

In the year 2004, VLSI Design and Education Center (VDEC) has got an important donation from ADVANTEST corporation. The donation included the state-of-the-art 8-inch electron beam (EB) direct writer F5112. The EB machine is installed in the Federal Class 1 supercleanroom in Takeda building. The EB machine is opened to academics since April 2005. Although ADVANTEST corporation now proposes 300mm EB writing machine F3000 as their latest series, the VDEC F5112 keeps offering quite comparable perfomance in terms of EB pattern resolution.

After two academic years' common usage, total 71 students and faculty staffs of more than 30 laboratoires, mainly from the University of Tokyo, are licenced. Nearly 1000 exposures are performed per year. As a consequence, competitiveness in MEMS field of those groups are increasing. For example, F5112 user laboratories share more than 13% of world's papers*¹ in MEMS conference , which is the most important worldwide conference and the acceptance ratio is quite low (5% for oral, 25% for poster presentations). The VDEC's EB support team is proud to underline that the competitiveness is not only because of F5112's fine resolution and rapid writing*² characteristics, but also because of the University of Tokyo Extention of the apparatus; the UT version of F5112 (F5112+VD01) can write on arbitral shapes and sizes of samples and photomasks (see below for details).

From the year 2007, "Nanotech Network" funding program is launched by Japanese Minstry of Education (METI). Our EB apparatus participates as the U.Tokyo's network site together with Faculty of Engineering's Electron Beam Microscopes cluster, including the world's highest resolution Transmission Electron-Beam Microscope (TEM). This program will help us to open the apparatus to even more laboratories, especially extern to the U.Tokyo.

(*1) Example of MEMS2006 for Oral, 2007 for bothe Oral and Poster
MEMS2006 Oral:Total 41 papers/including U.Tokyo 8 papers/incl. F5112 group 5 papers. MEMS2006 Poster:Total 186 papers/including U.Tokyo 13 papers/incl. F5112 group 9 papers. MEMS2007 Oral:Total 43 papers/including U.Tokyo 6 papers/incl. F5112 group 6 papers. MEMS2007 Poster:Total 142 papers/including U.Tokyo 20 papers/incl. F5112 group 19 papers.
(*2) Writing speed of F5112 is 10 to 100 times as fast as "ordinal Electron Beam" writer. Nominal exposure time over 4 inch entire wafer is within 30 minutes.

Exposure Example

The apparatus

1 Coating System

2 Electron Beam Writer F5112+VD01

3 Wet Mask Etching System

4 Cleaning/Descum System

5 Pattern Verificaiton Microscope

1 Coating System

1-1 Spin Coater SC-400

Specification:

Specification	Value
Rotation	60 to 6000rpm
Steps	2 steps

Placed on the chemical evacuation table.

1-2 Oven DNF-44

Temperature 30 to 260 degree Celsius.

Can accomodate up to 8 inch arbitrary shape can be put.

Gas exhaust is possible.

2 Electron Beam Writer F5112+VD01

• Specification
  
  

  Specification	Value
  Guaranteed pattern resolution	100nm
  Pattern size tolerance	15nm(3 sigma)
  Field conjugation tolerance	Less than 40nm for |average|+3 sigma
  EB shape	Variable Square Beam and Character Block Exposure

  
  
• Functions
  
  

  Specification	Value
  Acceleration	50kV
  Exposure Type	On-the-fly (OTF) exposure, Step & repeat (SR) exposure. Stage is deceleratable for large shot numbers.
  Wafer size	up to 8 inch round
  Loader	Single

• Sample size (Unique feature of VD01)
  
  • 4 inch (4009) quartz mask
  • 5 inch (5009) quartz mask
  • 2 inch 270um-thick round wafer
  • 3 inch 380um-thick round wafer
  • 4 inch 525um-thick round wafer
  • 1.0x1.0 to 3.0x3.0cm arbitral shape wafers (thickness: 325um, 425um, 525um, or 725um)
  • 8 inch 725um-thick round wafer (*)
  Other size and thickness can be accomodated by preparing dedicated adjuster.
  (* Alignment mark is obligatory on the wafer.)
  

3 Wet Mask Etching System

3-1 Wet Mask Developer APT3150

Can accomodate 3,4,5,6,7inch mask blank and 3,4,5,6,7inch round wafers.

Includes chemical exhaust system.

Automatic development, rinsing, and spin-dry.

3-2 Wet Mask Etcher APT1140

Can accomodate 3,4,5,6,7inch mask blank and 3,4,5,6,7inch round wafers.

Automatic development, rinsing, and spin-dry.

4 Cleaning/Descum System

4-1 Cleaner

Can accomodate 3,4,5,6,7inch mask blank and 3,4,5,6,7inch round wafers.

Automatic H₂SO₄ cleaning, scrub cleaning, rinsing, and spin dry.

4-2 Plasma Asher PAC-III

Can accomodate 3,4,5,6,7inch mask blank and 3,4,5,6,7inch round wafers.

Two mass flow control system.

Short turn around time.

5 Pattern Verificaiton Microscope 1LM21

5-1 LASER Microscope

Features below:

Specification	Value
Resolution	0.25um
Light Source	He-Ne LASER
Scan Frequency	Horizontal 15.73kHz Vertical 60Hz
Least Significant Bit of scale	0.001um
Scale Error	plus minus 0.03um
gamma correction	possible

LASER scanning microscope, motor driven stage, antivibration stage, and monitor.

3 dimensional image processing software bundled.

Stage is addressable by plus minus 2 micron resolution.