Library of Congress Cataloging in Publication Data

Mattis, Richard L.

A BASIC Program for Calculating Dopant Density Profiles
from Capacitance - Voltage Data.

(Semiconductor Measurement Technology) (National Bureau
of Standards Special Publication; 400-11)

Supt. of Docs. No.: C 13.10:400-11

1. Electronic Data Processing-Ion Implantation. 2. Electronic
Data Processing-Diodes, Semiconductor. 3. Electronic Data
Processing-Electric Measurements. 4. BASIC (Computer Pro-
gram Language) I. Buehler, Martin G., joint author. II. United
States. National Bureau of Standards. III. Title. IV. Series. V.
Series: United States. National Bureau of Standards. Special Pub-
lication; 400-11. QC100.U57 No. 400-11 [TK7871.85] 389'.08s
[621.3815'.2'028] 75-619089

National Bureau of Standards Special Publication 400-11
Nat. Bur. Stand. (U.S.), Spec. Publ. 400-11, 39 pages (June 1975)
CODEN: XNBSAV

U.S. GOVERNMENT PRINTING OFFICE
WASHINGTON: 1975

For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402
(Order by SD Catalog No. C13.10:400-11). Price $1.00 (Add 25 percent additional for other than U.S. mailing.)

LIST OF FIGURES

Figure 1. Schematic representation of the depletion region of a p-n junction diode diffused in an epitaxial semiconductor .

Page

Figure 2.

Semilog plot of the function x = erfc (y) showing the transformed variable

Figure 3.

Calculation of y = erfc-1(x) by means of a parabolic fit

7

Figure 4. Flow chart of the PLOT subroutine

10

Figure 5.

A plot artificially constructed to show the six types of printed output of
the PLOT subroutine

12

Figure 6.

Summary flow chart of program CV1

133

PREFACE

This work was carried out as a part of the Semiconductor Technology Program in the Electronic Technology Division at the National Bureau of Standards. The Semiconductor Technology Program serves to focus NBS efforts to enhance the performance, interchangeability, and reliability of discrete semiconductor devices and integrated circuits through improvements in measurement technology for use in specifying materials and devices in national and international commerce and for use by industry in controlling device fabrication processes. The Program receives direct financial support principally from three major sponsors: The Defense Advanced Research Projects Agency (ARPA), The Defense Nuclear Agency (DNA) and the National Bureau of Standards. The specific work reported herein was supported by ARPA.*

The computer program CV1, the subject of this report, is derived from a program reported by D. B. DeVries, G. Lee, and S. Watelski in Integrated-Circuit Process Control and Development, Technical Report AFAL-TR-73-268, August 1973. The present program contains improvements in the peripheral capacitance correction, the error function calculations, the numerical integration, the plot routine, and data input/output. The present report is intended as a guide for persons using the program described herein. detailed comparison of the present and the original programs.

It is not intended to provide a

The authors are indebted to several persons who assisted in the editing and preparation of this report. Gerard N. Stenbakken performed a critical and constructive reading of the text. The several figures were prepared by Edgar C. Watts and Leo R. Williams. of the final draft was done by Frances C. Butler.

The typing

Through ARPA Order 2397, Program Code 4D10.