Power Tools for Technical Communication:
Memo Revision


In this lab, you revise a rather badly written memo:
  1. Copy the text below this box, and paste it into your preferred word-processing software.
  2. Study the text carefully, looking particularly for paragraph breaks, wordiness. Only after you've tightened up and focused the text, revise for spelling, punctuation, and usage problems.
  3. See if you can add headings and lists and rework some of the text as tables.
  4. Imitate the memo format with DATE:, TO:, FROM:, and SUBJ.: lines at the top of this revison.
  5. Either show your instructor your completed work; or put your name, Memo Revision, and the date on this document, and print it out for your instructor.


Address this memo to the wireless subscriber group manager (make up a name); make the memo from you, the writer. Use the current date and indicate the subject as an update on rapid response analysis with a corrective action plan.

I am submitting to you, the wireless subscriber group, an update on the developments and progress that has been made on the rapid response analysis for the ESD failures (KL22557 chip) found during reliability testing. The TSG failure analysis lab began studying and analyzing the LK22557 chip two days ago, immediately after recieving the failing device with a request for analysis. The purpose of this project is to analyze the failing device, find the failure mechanism, identify a root cause and recomend a corrective action plan. A three day rapid response analysis with corrective action plans have been guaranteed. The KL22557 lot production is currently on hold due to electrostatic discharge damage detected during reliability testing. The customer for the KL22557 is ready for the production of their cellular phones, but cannot procede without the KL22557 chip. Time is a critical, essential factor and a fast analysis and a corrective action plan is a high priority. The analysis will be broken down into three phases;

Day one. Varifications of failure, external inspection, x-ray examination, chemical decapsulation, internal inspection, liquid crystal analysis.

Day 2. Emmission microscopy, chemical deprocessing.

Day 3. Completion of an analysis report with a corrective action plan

As of this point in time, the analyses of the chip has been completed and the submission of the final report will be before the end of the business day tomorrow. Here is a break down of the analysis that has been completed.

Performance of a curve trace of all the pins on KL2257 chips were done to indentify any failing pins. A Tektronix curve tracer was implemented to measure and calculate current flow. A leaky I/O pin was detected with a bad trace. Photos of the bad trace in comparison to the trace of a known good device will be displayed. The report will detail the process used for curve tracing this device. Also include will be a x-ray photograph of the device to show that the failure was not due to a packaging problem. The report will also detail the decapsulation process utilizing wet and dry etches. Chemical decapsulation was accomplished with no problems. An internal optical inspection was done with no visible defects. Photos of any defects detected during the optical inspection would be displayed here. A light camera analysis was done with a visible emission site. The emission site permitted the isolation of the failing area on the KL22557 chip. The report will detail the methodology and procedure for light emission analysis. A photo of the emission site showing the failing area will be included in the report.

After locating an emission site with the light camera, liquid crystal was implemented in the confirmation of the location of the failure. Liquid crystal displayed a hot spot at the emission site, confirming the leakage area. The report will detail the procedure for using liquid crystal. After deprocessing the device down to a silicon layer a discovery of the failing mechanisms was made. A SEM analysis of the emmission site detected a spiked contact and multiple gate rupture to the N channel protection circuitry. The defects that were discovered are common and typical of ESD damage. An outline the procedure that was used to deprocess the device down to the silicon layer as well as SEM micrographs of the defects will be included in the final report. Multiple gate ruptures and a spiked contact was discovered during the analyses. The damage was detected in the ESD protection circuitry of an I/O pin. This type of damage is typical of ESD. Currently, all analyses has been completed and all that remains is a final report and corrective action plan. The completion of the analysis of the failing device was made according to schedules with no problems, and the processes and techniques used in the analysis will be more detailed in the final report. We do not expect any problems with the final report being delivered on time and expect to have a feasable corrective action plan to recomend.


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