A methodology for selecting a vendor to collaborate with for the development of a new analytical probing system used for on-wafer device characterization in the hardware verification of compact device models in process design kits (PDK).

1. Developing a New Auto-
Loading Analytical Prober
Phillip Corson
September 2013
August 20131

2. ∗ Goal
∗ Background
∗ Evaluation Process
∗ Requirements
∗ Evaluation
∗ Acceptance
∗ Summary
August 20132
Agenda

3. ∗ Create a set of requirements for an auto-loading analytical
prober used in design kit verification
∗ Must be able to meet or exceed the leakage,
noise, and thermal performance of the best-of-
breed analytical probers
∗ Support loading of multiple designs within a wafer
carrier
∗ Provide loading from multiple wafer carriers and
allow each carrier to have a different wafer size
∗ Capable of supporting all measurements required
for design kit verification
August 20133
Goal

4. ∗ The majority of auto-loading prober are intended to
manufacturing production use
∗ Most have minimal noise shielding
∗ Often have a limited thermal range
∗ Many have high internal noise generation
∗ Designed for speed so vibration sensitive measurement can
be compromised
∗ Analytical probers are designed for difficult, high precision
measurements
∗ Capable of operating below the test instruments noise floor
∗ Ultra-stable for long duration measurements
∗ Net: Probers for analytical use require a very different
design point than production probers
August 20134
Background

5. ∗ Assemble group of key stakeholders
∗ Lab engineers and technicians
∗ Buyer responsible for vendor interface
∗ Management support
∗ Create a list of requirements and evaluation criteria
∗ Send list of requirements and request a response from
all approved suppliers
∗ Evaluate vendor responses against evaluation criteria
∗ Select vendor for collaboration
August 20135
Evaluation Process

6. ∗ Measurement of DC I/V and C/V, flicker noise, high speed
pulse, S-Parameters, and noise parameters
∗ Controllable through test executive
∗ Built-in anti-vibration
∗ Full temperature range testing from -60C to 200C
∗ Chamber shielding for light, electrical and magnetic noise,
and ambient environment
∗ Prober card and multiple positioner mounted DC/RF probes
∗ Multiple auxiliary chucks for probe cleaning and ISS
∗ Automatic wafer loading, alignment, and set to initial
location
August 20136
Requirements

7. ∗ Microscope for inspection of final probe to pad alignment
∗ Manual override and retention of automatic alignment
∗ Console operation from remote computer
∗ Wafer serial number reader and map to carrier slot
∗ Different size wafers in each carrier
∗ Arbitrary wafer loading by carrier/slot or wafer serial
number
∗ Chamber purge with CDA or nitrogen
∗ Triaxial chuck connection with a minimum bias range of -500
to 500 volts
∗ Automated temperature transitioning and realignment
August 20137
Requirements (cont.)

8. ∗ Stakeholders review initial responses and select
leading candidates for detailed evaluation
∗ Notify candidates of missing or ambiguous items in
response
∗ Request formal presentation from each vendor with
details of the proposed solution
∗ Complete formal evaluation
∗ Technical team handles specifications
∗ Buyer handles financials
August 20138
Evaluation

9. ∗ Formal evaluation example
August 20139
Evaluation (cont.)
Category Weight Sub Category Weight
Person A Person B Person C Person D Avg Score Person A Person B Person C Person D Avg Score
Performance 20% Thermal Cycling & Control 10% 8.0 9.5 9.0 10.0 9.1 8.0 9.5 6.0 8.0 7.9
Noise levels - leakage and AC 25% 7.0 7.5 10.0 8.0 8.1 7.0 8.0 7.0 9.0 7.8
Stepping Accuarcy 25% 9.0 8.0 10.0 10.0 9.3 8.0 9.0 5.0 8.0 7.5
Robotics 20% 9.0 9.0 10.0 8.0 9.0 6.0 9.0 7.0 7.0 7.3
Temp sweep/cleaning 15% 9.0 7.5 10.0 10.0 9.1 5.0 7.0 3.0 6.0 5.3
High Resolution Imaging 5% 7.0 7.0 10.0 8.0 8.0 8.0 9.0 7.0 10.0 8.5
100%
Weighted Score = 1.7 1.6 2.0 1.8 1.8 1.4 1.7 1.2 1.6 1.5
Ease of Use 20% Operating Software 30% 9.0 8.0 9.0 9.0 8.8 6.0 8.5 8.0 6.0 7.1
Programming Ease/GPIB 30% 8.0 7.5 8.0 8.0 7.9 8.0 7.5 7.0 9.0 7.9
Remote operation 20% 7.0 7.0 8.0 8.0 7.5 8.0 9.0 9.0 9.0 8.8
tool setup and wafer maps 20% 8.0 7.0 9.0 8.0 8.0 7.0 8.5 8.0 8.0 7.9
100%
Weighted Score = 1.6 1.5 1.7 1.7 1.6 1.4 1.7 1.6 1.6 1.6
Serviceability 10% Response Time 20% 9.0 8.0 10.0 9.0 9.0 7.0 7.5 6.0 7.0 6.9
Problem Resolution 25% 7.0 7.5 9.0 7.0 7.6 8.0 8.0 6.0 8.0 7.5
Test Exec/Programming support 20% 8.0 8.5 9.0 7.0 8.1 8.0 8.8 9.0 7.0 8.2
Hardware/Software Intergration risk 35% 8.0 6.5 9.0 6.0 7.4 8.0 9.0 8.0 7.0 8.0
100%
Weighted Score = 0.8 0.7 0.9 0.7 0.8 0.8 0.8 0.7 0.7 0.8
Price 50% Cost of Ownership 100% 8.0 8.5
Weighted Score = 4.00 4.25
Grand Total of Weighted Scores = 8.17 8.04
Vendor 1 Vendor 2
∗ Vendor with highest score awarded contract

10. ∗ All requirements are translated into verifiable actions
with pass/fail criteria
August 201310
Acceptance
Performance Metric Specification Measurement Pass/Fail
Mechanical Performance
Stage travel X (mm) 305 308 Pass
Stage travel Y (mm) 505 510 Pass
Stage travel Z (mm) 12 12.5 Pass
Stage travel Theta (Deg) 7.5 7.7 Pass
Accuracy X (um) 3 2.4 Pass
Accuracy Y (um) 3 2.7 Pass
Repeatability X (um) 1.5 1.2 Pass
Repeatability Y (um) 1.5 1.3 Pass
Repeatability Z (um) 1.5 1.1 Pass
Thermal Performance
Minimum Temp (C) -60 -60 Pass
Maximum Temp (C) 200 200 Pass
Uniformity (dig C) 0.1 0.1 Pass
Ramp time 25C to 150C N/A 15.5 Acceptable
Ramp time 150C to 25C N/A 22 Acceptable
Performance Metric Specification Measurement Pass/Fail
Electrical Performance
Chuck Resistance - Force to
Guard (ohm) 5.E+12 1.E+13 Pass
Chuck Resistance - Force to
Shield (ohm) 5.E+12 1.E+13 Pass
Chuck Resistance - Guard to
Shield (ohm) 5.E+12 9.E+12 Pass
Chuck Breakdown - Force to
Guard (V) 500 500 Pass
Chuck Breakdown - Force to
Shield (V) 500 500 Pass
Chuck DC Leakage @ -40C (fA) 25 21 Pass
Chuck DC Leakage @ -25C (fA) 15 12 Pass
Chuck DC Leakage @ -200C
(fA) 25 23 Pass
Chuck AC Noise (mV p-p) 5 3 Pass

11. ∗ Created detailed specification with the lab team and
requested proposals from multiple vendors for initial
evaluation
∗ Selected top vendors and completed a detailed evaluation
∗ Selected the best-of-breed vendor and developed strong
relationship resulting in the Cascade CM300 family of
automatic analytical probers
∗ Drove progress throughout the development
project and implementation with challenging
acceptance criteria
August 201311
Summary