SEMI International Standards
Standards New Activity Report Form (SNARF)
Date Prepared: 07/09/2019Revised (if Applicable):

Document Number: 6554
SNARF for: New Standard: Practice for Carrier profiling of semiconductors by Scanning Capacitance Microscopy and Scanning Spreading Resistance Microscopy

Originating Global Technical Committee: Silicon Wafer
Originating TC Chapter: North America
Task Force (TF) in which work is to be carried out: International Test Methods Task Force
Note: If a new task force is needed, also submit a task force organization form (TFOF)

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1. Rationale:
a. Describe the need or problem addressed by this activity.
(Indicate the customer, what benefits they will receive, and if possible, quantify the impact on the return on investment [ROI] if the Document is implemented.)

The two procedures most often used for carrier profiling in the semiconductor industry, Scanning Capacitance Microscopy (SCM) and Scanning Spreading Resistance Microscopy (SSRM), are not described in present SEMI standards. However, both of them are now used at the fine technology nodes (e.g. to 7-nm) where their resolution is comparable to the node dimension.

Limitations in these two procedures were noted much earlier at the 45-nm node. In August of 2018 GlobalFoundries put the 7-nm node “on hold” citing metrology as one issue. Furthermore, analysis of the data for 2D-NAND flash memory shows that over an eight-year period, as the chip capacity was increased by 100-fold, the endurance limits (number of reliable state changes) decreased in each step to a finer lithography so the reliable capacity has actually stagnated.

We attribute this problem with flash memory to the need for better practice in measuring the insulation of the floating gates that are used for storage which is possible using SSRM and we will define in this practice.




b. Estimate effect on industry.
1: Major effect on entire industry or on multiple important industry sectors - identify the relevant sectors
Sector or Company Information: Fabs: Front-end-of-line device metrology, failure analysis, site-specific.

c. Estimate technical difficulty of the activity.
II: Some Difficulty - Disagreements on known requirements exist but developing consensus is possible

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2. Scope:
a: Describe the technical areas to be covered or addressed by this Document development activity. For Subordinate Standards, list common concepts or criteria that the Subordinate Standard inherits from the Primary Standard, as well as differences from the Primary Standard:
Our working group will prepare the first SEMI standard for the practice of carrier profiling semiconductors by scanning capacitance microscopy (SCM) and scanning spreading resistance microscopy (SSRM). We will emphasize the present urgent needs of the semiconductor industry at and beyond the 7-nm technology node. Ultimately it may be necessary to implement a new technology for carrier profiling but first it is necessary to clarify and optimize practices using the present methods of SCM and SSRM.

We will be the first to address the issue of repeatability in SCM and SSRM, noting that the repeatability of measurements at a fixed location on the sample must be known before it is appropriate to address the issue of resolution where the measurements are made at multiple locations on a sample.

We will define “resolution” and redefine “node” which has lost its meaning or use another word to denote the minimum size of the relevant features in a semiconductor device. Then we will be able to recommend what resolution is required for a specific device.

It is often stated that the size of the contact of an SSRM or SCM probe with a semiconductor is what limits the resolution in carrier profiling. However, there are fundamental limits for the resolution. For example, the resistivity, which is measured in SSRM, is undefined in a length that is less than the mean-free path for the carriers. Debye smearing sets a fundamental limit to the resolution in carrier profiling. Understanding these concepts will provide reasonable delimitations for carrier profiling.

b: Expected result of activity
New Standard or Safety Guideline (including replacement of an existing Standard or Safety Guideline)

For a new Subordinate Standard, identify the Primary Standard here:




For Standards, identify the Standard Subtype below:
Practice

Miscellaneous (describe below):

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3. Projected Timetable for Completion:

a: General Milestones
a. Activity Start: 07/09/2019b. 1st Draft by: 03/30/2020
c. (Optional) Informational Ballot by: d. Letter Ballot by: 05/01/2020
e. TC Chapter Approval By:07/01/2020

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4. Liaisons with other Global Technical Committees/TC Chapters/Subcommittees/TFs:
a. List SEMI global technical committees, TC Chapters, subcommittees, or task forces in your or other Regions/Locales that should be kept informed regarding the progress of this activity. (Refer to SEMI Standards organization charts and global technical committee charters and scopes as needed.)


b. List any planned Type I Liaisons with external nonprofit organizations (e.g., SDO) that should receive Draft Documents from Standards staff for feedback during this activity and be notified when the Letter Ballot is issued (refer to Procedure Manual § 7):


c. Intercommittee Ballots:
will not be issued

Identify the recipient global technical committee(s):

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5. Safety Considerations:
The resulting document is expected:
NOT to be a Safety Guideline

NOTE FOR "to be a Safety Guideline": When all safety-related information is removed from the Document, the Document is NOT technically sound and complete - Refer to Section 15.1 of the Regulations for special procedures to be followed.

NOTE FOR "NOT to be a Safety Guideline": When all safety-related information is removed from the Document, the Document is still technically sound and complete.

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6. Intellectual Property Considerations:
Note: Both a: and b: below should be checked for Revision of existing Standard(s) and Safety Guideline(s).

a. For a new Standard or Safety Guideline and for any part to be modified or added in a Revision of published Standards and Safety Guidelines:
the use of patented technology is NOT required.

If "patented technology is intended to be included in the proposed Standard(s) or Safety Guideline(s) " is selected above, then also check one:


b. For Revision, Reapproval, Reinstatement, or Withdrawal of existing Standard(s) and Safety Guideline(s):
there is no known material patented technology necessary to use or implement the Standard(s) and Safety Guideline(s)

c. The body of the Document and any Appendices, Complementary Files, Related Information sections, or Various Materials that may or may not be a part of the Document by reference:
the incorporation of Copyrighted Item will NOT be required



NOTE FOR ‘the use of patented technology or the incorporation of Copyrighted Item(s) is NOT required’: If in the course of developing the Document, it is determined that the use of patented technology or Copyrighted Item(s) is necessary for the Document, the provisions of Regulations § 16 must be followed.

NOTE FOR ’will incorporate Copyrighted Item’: A copyright release letter must be obtained from the copyright owner prior to publication.

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7. Comments, Special Circumstances:
None.

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8. TC Member Review:
took place between (put dates below ) before approval at the TC Chapter Meeting, or

Member Review Start Date; 6/25/2019.
Member Review End Date: 7/9/2019

NOTE FOR ‘TC Member Review’ is required by the Regulations for a period of at least two weeks
before approval of a new, or a major revision of an existing, Standard or Safety Guideline. (Refer to Regulations ¶ 8.2.1)
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9. SNARF Approval Dates:
TC Chapter or GCS07/09/2019
Recorded in TC Minutes07/09/2019

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10. SNARF Extension Dates:
TC Chapter Extension Granted on
Extension Expires on