HF/HNO3 Monitor, CS-153N

Overview

The CS-153N is a high-precision chemical solution concentration monitor designed to meet the strict demands of semiconductor wet-etching processes. Etching processes use HF/HNO3 solution to etch silicon oxide and remove particles from the wafer surface. The CS-153N continually monitors each component of the HF/HNO3 solution (HF/HNO3/H2O), alerting the user each time the solution is replaced or replenished. This allows you to maintain the concentration of the HF/HNO3 solution within the tolerance range, while eliminating unnecessary solution replacement.

Features

  • Short 3-second measurement cycle supports concentration control for 300-mm processes
    A short measurement cycle of approximately three seconds makes it possible to track concentrations at much closer to real time. Supports fine-tuned concentration control for batch-type-bath as well as single-bath cleaning devices.
  • Compact design helps reduce cleaning-device footprint
    The compact design reduces the monitor's footprint by about a third*, reducing the amount of space required by the cleaning device. The monitor is easily integrated with the cleaning device.
    *Based on comparison with the HORIBA CS-327 series.
  • Reduces lot defects in the cleaning process for improved yield
    Output from the monitor is used for automated spiking control of the HF/HNO3 solutions, enabling cleaning with a high reproducibility rate. As a result, lot defects decrease in the cleaning process, which helps to boost the overall yield.
  • Fully automated measurement simplifies control
    All the user has to do is set up the HF/HNO3 solution supply. Measurement is fully automatic, so no control whatsoever is required once the measurement has begun. Also, air is used for reference spectral measurement, and water concentrations can also be measured, which allows continuous tracking of changes in water concentration due to evaporation of the solution and adherence to the wafer. This allows fine-tuned control of silicon-oxide etching.
  • Comprehensive measures to eliminate air bubbles enable continuous measurement
    A built-in bubble removal function removes air bubbles immediately before the flow cell, which allows continuous measurement of the solution as it is flowing.
  • 24 V DC used for improved safety
    The monitor uses a low-voltage (24 V DC), and running on about 45 W gives it even better electric-shock safety and energy efficiency. An internal leakage sensor is also installed to detect solution leaks, so that the supply of HF/HNO3 solutions can be shut off in the event of an emergency.

Manufactured by HORIBA Advanced Techno

Specifications

Model specifications

CS-153N: No cooling unit

CS-153NC: Integrated cooling unit

Measurement sample

HF/HNO3(HF/HNO3solution)

Measurement principle

Absorption spectrometry

Concentration computation principle

Temperature-compensated multivariate analysis

Measurement range

HNO3: 57.0 to 65.0%

HF: 3.00 to 8.00%

H2O: 27.0 to 40.0%

Please consult HORIBA for information concerning other measurement ranges.

Reproducibility (Peak to peak)

HNO3:  ± 0.3%

HF: ± 0.25%

H2O: ± 0.5%

Chemical conditions

CS-153N:

Temperature: 20 to 30°C

Flow rate: 20 to 60 mL/min.

Pressure: 0.10 to 0.20 MPa

CS-153NC:

Temperature: 20 to 80°C

Flow rate: 20 to 40 mL/min.

Pressure: 0.10 to 0.20 MPa

Measurement cycle

Approx. 2 seconds minimum

(not including chemical replacement and cooling times)

Equipment temperature

20 to 25

Operation panel

1) Temperature level display:  HNO3, HF: , water

2) Alarm display: HNO3, HF: Concentration low-low limit, concentration low limit, concentration high limit, concentration high-high limit

3) Alarm value settings:  HNO3, HF: Concentration low-low limit, concentration low limit, concentration high limit, concentration high-high limit

Serial input/output

RS-232C

1) Concentration data:  HNO3, HF

2) Alarm value settings:  HNO3, HF:  Concentration low-low limit, concentration low limit, concentration high limit, concentration high-high limit Parallel input 12 to 30 V DC (photocoupler insulated) Parallel concentration alarm (ON/OFF)

Parallel output

Maximum current when open collector output is ON: 5 mA

Maximum voltage when open collector output is OFF: 30 V

1) Alarm output:  HNO3, HF: Concentration low-low limit, concentration low limit, concentration high limit, concentration high-high limit

2) Device error

3) Liquid leakage

Analog output

4 to 20 mA (2 outputs:  HNO3 concentration, HF concentration) *Regardless of the range specifications, the output of 4 ~ 20 mA can be made to correspond to 0 ~ 10% concentrations.

(Please specify when ordering.)

Power supply

24 V DC ± 10%, 2 A

Dimensions

CS-153N: 205 (W) x 329 (D) x 269 (H) mm

CS-153NC: 291 (W) x 329 (D) x 269 (H) mm

Weight

CS-153N: Approx. 11 kg

CS-153NC: Approx. 12 kg

Connection pipe size

For input and exhaust: Outer diameter 3 mm (inner diameter 2 mm)

Pipe connection

Nippon Pillar Super type