Modeli ing ng and analysis of RF LDMOS for reliability issues and - PowerPoint PPT Presentation

Modeli ing ng and analysis of RF LDMOS for reliability issues and analysis of RF LDMOS for reliability issues Model M. Gares, M. A. Belaid, H. Maanane , M. Masmoudi, J. Marcon, K. Mourgues and Ph. Eudeline MOS AK WORKSHOP Boeblingen, March 24, 2006 E lectronic M icrotechnology & I nstrumentation L aboratory 1

Presentation outline Presentation outline Context of of this study this study Context ► ► Objectives Objectives ► ► Innovative reliability bench bench Innovative reliability ► ► DC and CV characterization DC and CV characterization ► ► RF LDMOS modeling modeling RF LDMOS ► ► ► Conclusion & prospects Conclusion & prospects ► 2

Context of of this study this study Context Reliability improvement of amplifier stages for S of amplifier stages for S Band Band Reliability improvement radar (2- -4 4 GHz GHz) ) radar (2 3

Presentation outline Presentation outline Context of of this study this study Context ► ► Objectives Objectives ► ► Innovative reliability bench bench Innovative reliability ► ► DC and CV characterization DC and CV characterization ► ► RF LDMOS modeling modeling RF LDMOS ► ► ► Conclusion & prospects Conclusion & prospects ► 4

Objectives (1) Objectives (1) Objectives (1) � Characterization and Characterization and modeling modeling for reliability issues for reliability issues � � Obtaining Obtaining a set of significant parameters a set of significant parameters � such as t such as transconductance ransconductance (G (G M M ) ), threshold voltage , threshold voltage (V (V TH TH ) ), , O On n- - state resistance (R (R ON ) and capacitances and capacitances (C (C RSS , C OSS ,… …). ). state resistance ON ) RSS , C OSS , � Correlation between RF LDMOS electrical parameter drifts Correlation between RF LDMOS electrical parameter drifts � and any kind of degradation phenomenon, after RF Life- and any kind of degradation phenomenon, after RF Life -tests tests (S S band band radar operating conditions). radar operating conditions). ( Electro-thermal modeling as a tool for RF LDMOS reliability study 5

Objectives (2) Objectives (2) I- -V and C V and C- -V V I- -V and C V and C- -V V I I characterization characterization characterization characterization Innovative Innovative Reliability Reliability bench bench Modeling before before Model ling ing after after Modeling Mode RF Life- -tests tests RF Life- -tests tests RF Life RF Life RF performances RF performances tracking tracking What is the Failure What is the Failure A set of significant A set of significant mechanism involved mechanism involved? ? parameters parameters 6

Presentation outline Presentation outline Context of of this study this study Context ► ► Objectives Objectives ► ► Innovative reliability bench bench Innovative reliability ► ► DC and CV characterization DC and CV characterization ► ► RF LDMOS modeling modeling RF LDMOS ► ► ► Conclusion & prospects Conclusion & prospects ► 7

Innovative reliability bench (1) bench (1) Innovative reliability Computer+BILT P OUT P IN 80 W amplifier Peak power RF Source meter Modulator Switchs RF 8 > 1 X 8 Circulator Att DUT Tuner 30 dB coupler 40 dB attenuator 20dB attenuator Switchs RF 8 > 1 P REF Average Power Meter 8

Innovative reliability bench (2) bench (2) Innovative reliability Innovative reliability bench (2) � A A microwave microwave part part � � A control/command part A control/command part piloted piloted by a by a dedicated dedicated software software � � Thermal module for Thermal module for each devices each devices � 9

Presentation outline Presentation outline Context of of this study this study Context ► ► Objectives Objectives ► ► Innovative reliability bench bench Innovative reliability ► ► DC and CV characterization DC and CV characterization ► ► RF LDMOS modeling modeling RF LDMOS ► ► ► Conclusion & prospects Conclusion & prospects ► 10

DC Characterization Characterization (1) (1) DC DC mesurement setup mesurement setup DC ICCAP BILT Peltier module 11

DC Characterization Characterization (2) (2) DC Results esults & & Measurement consistency Measurement consistency R Measured Measured I I DS DS - -V V DS DS characteristics characteristics Measured I I DS -V V GS characteristics Measured DS - GS characteristics Consistency Consistency of Data of Data Data management Data management Extraplated I Extraplated I DS DS - -V V GS GS characteristics characteristics 500 500 400 400 300 300 I DS [mA] I DS [mA] 200 200 100 100 0 0 3,5 4,0 4,5 5,0 5,5 6,0 0 5 10 15 20 25 V DS [V] V GS [V] Measured (symbols) Measured (symbols) and and extrapol extrapolated ated Measured (symbols) (symbols) and extrapolated and extrapolated Measured (continuous lines continuous lines) ) output output characteristics characteristics ( (continuous lines ( continuous lines) ) transfer characteristics transfer characteristics V DS V DS =0 =0… …26 V 26 V with with a a step step of of 520 mV 520 mV V DS V DS =0 =0… …26 V 26 V with with a a step step of of 4.33 V 4.33 V 12 V V GS GS =3.5 =3.5… …5.8 V 5.8 V with with a a step step of of 383 mV 383 mV V GS V GS =3.5 =3.5… …5.8 V 5.8 V with with a a step step of of 45 mV 45 mV

CV Characterizatio Characterization (1) n (1) CV localization of capacitances of capacitances localization C DS C GS C GD Gate Gate x x x Source Source Drain Drain y y y - body - body N-LDD N-LDD N+ N+ N+ N+ P P + + P P sinker sinker P+ Substrate RF LDMOS device device cross cross- -section section with its with its RF LDMOS intrinsic capacitances intrinsic capacitances 13

CV V Characterization Characterization (2) (2) C Primary capacitance capacitance measurements measurements Primary Measured C Measured C RSS RSS , C , C ISS ISS and and C C OSS OSS , , Fr Fre eq=1MHz q=1MHz and and V V DS DS =[0V, 30V] =[0V, 30V] at at room room temperature temperature 14

CV Characterization Characterization (3) (3) CV Intrinsic capacitance capacitance measurements measurements Intrinsic 16 Measured C GS vs. V GS 15 14 13 C GS [pF] 12 11 10 9 8 -6 -4 -2 0 2 4 6 8 V GS [V] Measured C C GS vs.V V GS profile (V (V DS = 0V and and Measured GS vs. GS profile DS = 0V Fre eq.=1 MHz) q.=1 MHz) at at room room temperature temperature. . Fr 15

Presentation outline Presentation outline Context of of this study this study Context ► ► Objectives Objectives ► ► Innovative reliability bench bench Innovative reliability ► ► DC and CV characterization DC and CV characterization ► ► RF LDMOS modeling modeling RF LDMOS ► ► ► Conclusion & prospects Conclusion & prospects ► 16

RF LDMOS modeling modeling RF LDMOS Improved MET LDMOS MET LDMOS Model Model overview overview Improved � An An empirical empirical large signal non large signal non- -linear linear model. model. � � An An electro electro thermal model thermal model including static and dynamic including static and dynamic thermal thermal � dependencies. . dependencies � An An electro electro thermal thermal model, model, taking taking into into account account self self heating heating � effects and temperature influence on LDMOS influence on LDMOS electric electric behaviour. behaviour. effects and temperature 17

RF LDMOS LDMOS modeling modeling RF Improved MET LDMO MET LDMOS Model S Model overview overview Improved L g L d C gd R gd R d R g D G C ds C gs + + C th_CP I d s R th_CP V ds R i - R sub C th_PH R th_PH Electric ∆ T P diss R s model C th_HA R th_HA L s + Ta - Thermal S model Large signal equivalent equivalent circuit of circuit of the the MET LDMOS model MET LDMOS model Large signal 18

RF LDMOS modeling modeling RF LDMOS Improved MET LDMOS model MET LDMOS model overview overview (thermal aspects) (thermal aspects) Improved T C H e a tF lo w ∆ = ⋅ + C T R P T R C h ip th _ C P th _ C P T P th _ CA diss a P a c k a g e C R R th _ P H C = ⋅ th _ P H T P I V th _C A th _ C A H diss ds ds H e a ts in k C R th _ H A th _ H A T A = + + R R R R th _ CA th _ CP th _ PH th _ HA A m b ie n ta ir 19