NanoFab Trainer Update

Nick Reeder, March 14, 2014

Change to Materials Database

• • Added Cl 2 +BCl 3 +CHCl 3 +N 2 plasma as an etchant. Retained the Cl 2 +He plasma, which I had added previously.

Williams’ 1996 paper has little data for Cl 2 +BCl 3 +CHCl 3 +N 2 plasma, and 2003 paper has none. See next slide for etch rates.

Etch Rates (nm/min) per Williams 1996 Cl2+BCl3+CHCl3+N2 Al + 2% Si Sputtered Ti Sputtered W Sputtered 600 W Si SiO2 Si3N4 Single crystal Poly n+ Poly undoped Wet oxide Dry oxide LTO undoped anneald Unan. PSG LPCVD Ann. PSG LPCVD Stoich LPCVD Low-stress LPCVD OCG820 positive resist Olin Hunt 6512 positive resist W 450 W 68 67 75 2W 174 93 86 630 630 Proposed Simulated Etch Rates (nm/min) Ag, Evap or Sputtered Al, Evap or Sputtered Au, Evap or Sputtered Cr, Evap or Sputtered Cu, Evap or Sputtered Ni, Evap or Sputtered Pt, Evap or Sputtered Ti, Evap, CVD, or Sputtered W, CVD or Sputtered Cl2+BCl3+CHCl3 +N2 0 + warn 600 0 + warn 0 + warn 0 + warn 0 + warn 0 + warn 0 + warn 10 Ge, Evap or Sputtered Si, Wafer or Evap or Sputtered 0 + warn 450 Al2O3, Evap or Sputtered SiO2, Thermal Evap or CVD or Sputtered Si3N4, Evap or CVD or Sputtered Ta2O5 TiO2 SPR 955 SU8 2015 0 + warn 71 90 0 + warn 0 + warn 630 630

•

Testing Dill Expose Code with Multiple Layers

– Next three slides compare 1-second exposure with layers of: Photoresist alone – Photoresist above SiO2 – Photoresist above Al

One-second exposure, 1.5 µm photoresist layer above Si substrate.

One-second exposure, 1.5 µm photoresist layer above 0.5 µm SiO2 layer above Si substrate.

One-second exposure, 1.5 µm photoresist layer above 0.5 µm Al layer above Si substrate.

•

Testing Dill Expose Code with Multiple Layers

– Next three slides compare 5-second exposure with layers of: Photoresist alone – Photoresist above SiO2 – Photoresist above Al

Five-second exposure, 1.5 µm photoresist layer above Si substrate.

Five-second exposure, 1.5 µm photoresist layer above 0.5 µm SiO2 layer above Si substrate.

Five-second exposure, 1.5 µm photoresist layer above 0.5 µm Al layer above Si substrate.

•

Question From Our Last Meeting

How to generate the incident beam profile at resist surface (as in the figure at right from p. 5 of Andrew’s photoresist chapter of mask opening, distance of mask from surface, and thickness of resist layer? ), given intensity, width

Date Added To-Do Item

3/16/12 Write code to provide top-down view of mask.

3/30/12 Add Cl 2 3/30/12 Write code to implement polish, given user parameters of grit size & time.

as an etchant.

3/30/12 Provide algorithm to determine polish rate given material and grit size.

4/20/12 Incorporate Andrew’s code for photoresist exposure.

4/20/12 Fix photoresist underhang problem in spin-coat code.

5/4/12 Write code to implement stopping powers of layers to determine whether underlying Si is doped during implantation.

5/27/12 Write code to implement lift-off.

5/29/12 Write code to implement bake of photoresist.

5/31/12 Provide realistic limits on the following user-provided parameters: pressure and temperature when performing CVD; dose and ion energy when performing implantation.

6/28/12 Niu suggests iterating etch code in seconds instead of minutes .

Provide look-up table data for 1.) CVD deposition rates based on user 1/18/13 supplied pressure & temperature; 2.) evaporation deposition rates based on user-supplied current & voltage; 3.) sputter deposition rates of Au, Ni, Pt, W, Si 3 N 4 , Ta 2 O 5 , TiO 2 , and Si based on user-supplied pressure & power.

1/18/13 Write code to implement annealing after implantation.

Who’s Responsible

NR NR NR JM NR NR NR NR NR AS NR AS NR

Date Finished

2/11/14 1/29/14 2/9/14 1/18/13 Write code to implement doping by diffusion.

NR

Date Added To-Do Item

3/1/13 4/14/13 6/19/13 10/23/13 10/30/13 11/3/13 11/3/13 1/17/14 1/28/14 Write code to implement projection lithography as well as contact lithography.

Decide whether to accept Nick’s suggested edits (sent on 4/14/13 and 5/8/13) to Andrew’s seventeen tutorial chapters.

Surinder suggests automatically filling in dialog-box parameters if user clicks a point in a “View Rate” graph.

Jamshid suggests providing link in dialog boxes to display the relevant “View Rate” graph.

Jamshid’s student Rajput suggests making it easier for user to know which solvents etch which materials.

Fix bug causing photoresist spikes per Jamshid’s student Chico.

Address performance issue per Jamshid’s student Jarrod.

Write code to track and plot time, cost, quality of user operations.

Provide algorithm for tracking time, cost, quality of user operations.

Write code to implement cleaning.

Write code to implement profilometer.

Record video clips (in .flv format) of lab operations.

Write online help text.

Test the trainer and report problems to Nick.

Revise CVD code to distinguish LPCVD and PECVD.

Provide empirical algorithm for finding intensity profile at resist surface given intensity, opening width, airgap, resist thickness.

Who’s Responsible

NR AS NR NR NR NR NR NR AS NR NR AS & JM NR

ALL

NR AS

Date Finished

1/21/14 1/21/14 1/6/14 2/2/14