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PERFORMANCE STUDY OF 1 BIT STATIC RAM BASED ON PROCESS TECHNOLOGIES

By

NADIAH BINTI MD TUMIRAN

DISSERTATION

Submitted to the Electrical & Electronics Engineering Programme in Partial Fulfillment of the Requirements

for the Degree

Bachelor of Engineering (Hons) (Electrical & Electronics Engineering)

Universiti Teknologi PETRONAS Bandar Seri Iskandar

31750 Tronoh Perak Darul Ridzuan

© Copyright 20 ll by

Nadiah Binti Md Tumiran, 201 I

Approved:

PERFORMANCE STUDY OF 1 BIT STATIC RAM BASED ON PROCESS TECHNOLOGIES

by

Nadiah Binti Md Tumiran

A Final Report submitted to the

Electrical & Electronics Engineering Programme Universiti Teknologi PETRONAS

in partial fulfilment of the requirement for the Bachelor of Engineering (Hons) (Electrical & Electronics Engineering)

(Assoc. Prof. Dr. Mohammad bin A wan) Project Supervisor

UNIVERSITI TEKNOLOGI PETRONAS TRONOH, PERAK

MAY2011

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CERTIFICATION OF ORIGINALITY

This is to certify that I am responsible for the work submitted in this project, that the original work is my own except as specified in the references and acknowledgements, and that the original work contained herein have not been undertaken or done by unspecified sources or persons.

(Nadiah Binti Md Tumiran)

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ABSTRACT

A basic memory cell of Static Random Access Memory (SRAM) topology consists of four transistors which act as a flip flop and two more transistors will act as pass transistor. In this study, experiment is done by varying the values of different variables that can affect the performance of basic memory cell. Among the variables are magnitudes of voltage supply, temperature, clock frequency and process technology to be used in fabrication of memory cell. These variables will have their own limit due to the configuration of circuit and properties transistor parameters in the memory cell. These values will determine the performance of the memory cell. The studies are carried out using various process technologies by simulation at schematic level. The results show that higher clock frequency will require higher value of supplied voltage. Lower supplied voltage will make SRAM failed to operate at high temperature. Different process technology will also influence the value for minimum supplied voltage used and temperature range that the SRAM circuit can operate properly. The process technology of hpl4tb has the minimum voltage supply of0.83 Vat 5 MHz while amil6 has the widest effective range temperature from -229°C to 224°C at IOOMHz and 1.3 V simulation.

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ACKNOWLEDGMENTS

First and foremost, I would like to express my heartiest gratitude towards Allah the Almighty for without His grace and mercy, I would not be able to make through this Final Year Project I journey and complete it successfully within the time limit.

I would also like to express my deepest appreciation to my supervisor which is Assoc. Prof. Dr. Mohammad bin A wan for his support, encouragement, and guidance that he had given me throughout this period. I would also like to show my appreciation to technicians of Electrical and Electronic department for all the kind assistance they have been given me on fundamental knowledge of final year project, Cadence software and LINUX operating system. The supervision throughout this period was a great assistance and very much appreciated.

I would like to extend my appreciation to my family for their undying support and patience that let me complete this project.

Thank you.

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TABLE OF CONTENTS

ABSTRACT ... iv

ACKNOWLEDGMENT ... v

LIST OF FIGURES ... xi

LIST OF TABLES ... xii

LIST OF ABBREVIATION AND NOMENCLATURE ... xiii

CHAPTER 1: INTRODUCTION ... ! 1.1 Background of Study ... I 1.1.1 Semiconductor Memories ... ! 1.1.2 RAM ... 2

1.1.3 SRAM ... 2

1.1.4 SRAM History ... ... 2

1.1.5 Types ofSRAM ... ... 3

1.1.5.1 NMOS SRAM ... 4

1.1.5.2 CMOS SRAM ... 5

1.1.5.3 Fin-FET SRAM ... 5

1.2 Problem Statement ... 6

1.3 Objectives ... 6

1.4 Scope ofStudy ... 7

CHAPTER2: LITERATURE REVIEW ... 8

2.1 Digital Computer ... 8

2.2 Types of Semiconductor Memories ... 9

2.3 SRAM Memory Cells ... 1 0 2.4 SRAM Cell Operation ... 10

2.5 Pull-up Circuit ... 12

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2.6 Write Circuits ... .13

2. 7 Read Circuit.. ... 14

2.8 SRAM Circuit ... 15

CHAPTER3: METHODOLOG¥ ... 17

3.1 Procedure Identification ... 17

3.2 Tools and Equipment Used ... 19

3.2.1 Cadence Software ... ... .19

CHAPTER 4: RESULT AND DISCUSSION ... 21

4.1 Clock Frequency and Voltage Supply Effect. ... 21

4.2 Temperature Effect. ... 28

4.3 Process Teclmology Effect ... .33

CHAPTER 5: CONCLUSION AND RECOMMENDATION ... ... 37

5.1 Conclusion ... .37

5.2 Recommendation ... .37

REFERENCES ... ... .38

APPENDICES ... ... 40

APPENDIX I : Gantt Chart FYP I... ... .41

APPENDIX II :Gantt Chart FYP 1... ... .43

APPENDIX III : Schematic for Full Circuit of 1-bit SRAM by Using ami06 Process ... 44

APPENDIX IV : Read/Write Signal Properties ... .45

APPENDIX V : Data Signal Properties ... .46 APPENDIX VI : Simulation for Temperature of -250°C with

Vnn = 1.5 V and !eLK= 20 MHz by Using

ami 16 Process ... .4 7

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APPENDIX VII :Simulation for Temperature of243°C with ^Vvv= 1.5 V andfcLK= 20 MHz by Using amil6 Process ... .48

APPENDIX VIII : Simulation for Temperature of -229°C with Vvv = 5 V andfcLK= 100 MHz by Using amil6 Process ... .49

APPENDIX IX : Simulation for Temperature of290°C with Vvv

=

5 V and !eLK= 100 MHz by Using ami 16 Process ... .50 APPENDIX X : Simulation for Temperature of -250°C with Vvv = 1.8 V

andfcLK= 100 MHz by Using ami16 Process ... 51

APPENDIX XI : Simulation for Temperature of 57°C with ^Vvv

=

1.8 V andfcLK= 100 MHz by Using ami16 Process ... 52

APPENDIX XII : Simulation for Temperature of27°C with !eLK= 5 MHz by Using ami06 Process ... 53 APPENDIX XIII :Simulation for Temperature of27°C with fcLK= 10 MHz

by Using ami06 Process ... 54 APPENDIX XIV : Simulation for Temperature of27°C with !eLK= 5 MHz

by Using tsmc35 Process ... 55 APPENDIX XV : Simulation for Temperature of27°C with /eLK= 10 MHz

by Using tsmc35 Process ... 56 APPENDIX XVI :Simulation for Temperature of27°C with !eLK= 5 MHz

by Using hp14tb Process ... 57 APPENDIX XVII :Simulation for Temperature of27°C with !eLK= 10 MHz

by Using hp14tb Process ... 58 APPENDIX XVIII: Simulation for Temperature of -250°C with Vvv= 5 V

andfcLK= 20 MHz by Using tsmc35 Process ... .59

APPENDIX XIX : Simulation for Temperature of305°C with ^Vvv= 5 V

and !eLK= 20 MHz by Using tsmc35 Process ... 60

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APPENDIX XX : Simulation for Temperature of -240°C with VDD = 1.25 V andfaK

=

20 MHz by Using tsmc35 Process ... 61 APPENDIX XXI : Simulation for Temperature of 170°C with VDD = 1.25 V

and /eLK= 20 MHz by Using tsmc35 Process ... 62 APPENDIX XXII : Simulation for Temperature of -250°C with Vnn= 5 V

and !eLK= I 00 MHz by Using tsmc35 Process ... 63 APPENDIX XXIII : Simulation for Temperature of 305°C with Vnn = 5 V

andfcLK = 100 MHz by Using tsmc35 Process ... 64 APPENDIX XXIV : Simulation for Temperature of -230°C with Vnn = 1.25 V

andfaK

=

100 MHz by Using tsmc35 Process ... 65 APPENDIX XXV :Simulation for Temperature of 121

oc

^{with VDD= 1.25 V}

andfaK= 100 MHz by Using tsmc35 Process ... 66 APPENDIX XXVI : Simulation for Temperature of -250°C with Vnn

=

5 V

andfcLK= 20 MHz by Using hp14tb Process ... 67 APPENDIX XXVII :Simulation for Temperature of270°C with VDD= 5 V

andfcLK= 20 MHz by Using hp14tb Process ... 68 APPENDIX XXVIII: Simulation for Temperature of -117"C with Vnn= 0.91 V

andfcLK

=

20 MHz by Using hp14tb Process ... 69 APPENDIX XXIX :Simulation for Temperature of58°C with Vnn= 0.91 V

andfcLK= 20 MHz by Using hp14tb Process ... 70 APPENDIX XXX :Simulation for Temperature of -250°C with Vnn= 5 V

andfcLK= 100 MHz by Usinghpl4tb Process ... 71 APPENDIX XXXI :Simulation for Temperature of256°C with VDD= 5 V

and !eLK= 100 MHz by Using hp 14tb Process ... 72

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