CONFIDENTIAL WP2 Review Meeting Milan, October 05, 2011 MODERN ENIAC WP2 Meeting (WP2-T2.1) WP2 and Tasks review Milano Agrate, 2011 Oct. 05 Meeting hosted

CONFIDENTIALWP2 Review Meeting

Milan, October 05, 2011

MODERN ENIAC WP2 Meeting(WP2-T2.1)

WP2 and Tasks review

Milano Agrate, 2011 Oct. 05

Meeting hosted by Micron

CONFIDENTIAL 22

WP2: Relationship among work packages

WP2 Review MeetingMilan, October 05, 2011

CONFIDENTIAL 3

T2.1 Task

Task T2.1: PV-aware process simulation

Process simulation tools will be extended to include the impact of variations in TCAD simulations especially in etching and deposition processes; an interface to commercial process and device simulation programs will be developed. Process simulations for the extraction of behavioral models will be performed. In addition it is intended to build up an interface between the process simulation environment and the semiconductor FAB to obtain equipment parameters which affect variability.

Partners: ST-I, AMS, TUW

In the analysis and modelling of PV ST-I wants to link process information out of the silicon manufacturing facility into TCAD environment in order to take into account inevitable process variations and doping fluctuations with the objectives to create a behavioural model of the process to be simulated and to perform statistical process analysis and process optimization to improve parametric yield. AMS and TUW will focus on TCAD process simulation to reflect major sources for PV in 0.35um, 0.18um and 0.13um CMOS and HV technologies; main inline/equipment parameters will be taken into account. TCAD based statements about pros and cons of emerging device options will be given concerning variability. The methodology will be compared to the one used in task 2.2.


CONFIDENTIAL 4

Process simulation: T2.1 Deliverables

Ref Deliverable/ Contributors Due date

D2.1.1 First process simulation including treatment of PV for Discrete Power Device, HV-CMOS, SiC, GaN/AlGaN technologies, interfaced to commercial TCAD tools

(ST-I, AMS, TUW)

M15

DONE

D2.1.2 Enhanced process simulation including treatment of PV for Discrete Power Device, HV-CMOS, SiC, GaN/AlGaN technologies, interfaced to commercial TCAD tools

(ST-I, AMS, TUW)

M27

DONE

Task Leader: [email protected]

Partners: ST-I, AMS, TUW

Task 2.1 goal is to perform process simulation including treatment of PV. Application for discrete power devices, SiC, AlGaN/GaN (ST-I) and HV-CMOS technologies (AMS)


CONFIDENTIAL 5

Activity done so far:

– Interface between commercial process simulator and fab equipments: a web – based tool has

been realized. The tool accepts in input the product code used in manufacturing and produces in output the process parameters that can be passed to the TCAD software tools (Silvaco or Synopsys syntax) (Implementation activity is included in WP5)

– Process simulator setup & calibration– Process simulation with Synopsys platform has been performed.– Screening parameters: first device simulations have been executed in order to select the

process parameters that mainly affect the electrical behavior of the device: – Design of Experiment has been arranged to build structures with a systematic variation of the

selected process parameters.

The activity done on a Silicon Power MOS (D2.1.1) has been extended to compound materials (SiC and AlGaN/GaN devices) (D2.1.2)

– PCM extraction: polynomials function of process parameters have been extracted (T2.2)– PCM validation: As a check for the robustness of the PCM, a new set of simulation data,

choosing a random combination of input parameters, have been generated and compared with the prediction given by the PCM (T2.2)

Interactions

– T2.1 DOE results T2.2 for device simulation and PCM extraction.

T2.1 Review Summary (ST-I)


CONFIDENTIAL 6

Activity done so far, with highlights on technical results, and dissemination

- HV-CMOS technologies (AMS, TUW):• Statistical fab data analysis (FEOL, BEOL): 0.35µm HV-CMOS Tech. done• HV devices for DOE: NMOSI20T and PMOS20T• Process simulator setup & calibration done• Critical PV selection: 6 ~ 8 variables (substrate resistivity, implant dose, CD & overlay,

GOX thickness, …) done• PMOS20T process simulations with 7 PV variables done (see Back-up slides)• 286 (W/L=10/0.6, 10/10) structures from process simulations go to Minimos-NT for device

simulation.• Device simulations for statistical spice modeling: done (PMOS20T)• Script development for electrical parameter extraction inline measurement

D2.1.2 deliverable: Done

– An interface between commercial process simulator and Minimos-NT (a two-dimensional device simulator from TUW)

– Complete set of NMOS20T and PMOS20T process and device simulations done– Script update for electrical parameter extraction– NMOS20T and PMOS20T sensitivity analysis with 7~8 process variations: done

Issues

Interaction need:

– T2.1 results (HV-CMOS) T2.3 for Spice Monte-Carlo Model (D2.3.3)

T2.1 Review Summary (AMS, TUW)


CONFIDENTIAL 7

T2.1 Back-up slides for ST-I


CONFIDENTIAL 8

ST-I WP2 Activity

High Level factory

Process recipes

Specific process

conditions

Mask Layout

Process flowVirtual device

TCAD Experiments

Process Compact model

derived from TCAD

PCM

PCM

FAB1FAB1

FAB2FAB2

Technology Technology transferred to transferred to

FAB2 using PCMFAB2 using PCM


CONFIDENTIAL 9

WEB-Based Interface: High-level factory


CONFIDENTIAL 10

T2.1

10

Process compact modeling approach incorporates statistical design of experiment methods within the calibrated TCAD environment allowing to capture relationships between process variations and device performance through a set of analytic functions (Response Surface Method).

The flow of PCM extraction from TCAD simulation consists of the following steps:- Definition of a calibrated TCAD flow (process and device);- Analysis of process parameter sensitivity (parameter screening);- Simulations of process splits and electrical variables extraction (design of experiment);- PCM generation.

Input process parameters

Output device characteristics

Process Compact Model

Process Compact Model

Predicted device

response

New process conditions


CONFIDENTIAL 1111

Application to Power-Mos cell (D2.1.1)

Parameter screening to identify the process parameters that have an important impact on target electrical parameters.

Parameterized simulation setup (DOE) generating several simulation runs.

Device simulations of breakdown and I-V characteristic for each experiment.

DOE

EHD5 SEMICELL

SENTAURUS WORKBENCH

PCM STUDIO

PCM

Applied methodology flow.

Synopsys platform:Sentaurus and PCM Studio

Simulation of Power-Mos semi cell with the nominal values of the process input parameters


CONFIDENTIAL 12

Process variability

12

Variable Description

epithick Thickness of the epitaxial layer

epiconcDoping concentration of the epitaxial layer

gateox Thickness of the gate oxide

bmask CD of POLY gate mask

pmask CD of JFET mask

Input process parameters that have influence on the device behavior.

Output electrical parameters: RDSon and BV

A large number of process variables requires a very high computational cost.

Selecting only those process parameters showing the greatest impact on electrical performances.

0

2

4

6

8

10

12

14

16

epithick epiconc gateox bmask pmask

Ele

ctri

cal

par

amet

er v

aria

tio

n (

%)

Ron

BV

Sensitivity index for process parameter variation


CONFIDENTIAL 13

Design of experiments

13

The DOE depends on the degree of the polynomial required for a good data fit.

The output electrical parameter is a non-linear function of the input process parameters, modeled by a second order polynomial.

To fit a second-order model, a DOE with at least three levels is required: 81 experiments are generated.

For each structure, device simulations are performed to extract Ron and BV.

BV histogram

0

1

2

3

4

5

6

7

28

28

.8

29

.6

30

.4

31

.2 32

32

.8

33

.6

34

.4

35

.2 36

36

.8

37

.6

38

.4

39

.2 40

40

.8

41

.6

42

.4

43

.2 44

44

.8

BV (V)

BV

BV 5%

Ron histogram

0

1

2

3

4

5

6

7

8

9

9.1

9.5

9.9

10

.3

10

.7

11

.1

11

.5

11

.9

12

.3

12

.7

13

.1

13

.5

13

.9

14

.3

14

.7

15

.1

15

.5

15

.9

16

.3

Ron (m Ohm *m m 2)

Ron

Ron 5%


CONFIDENTIAL 14

Application to 4H-SiC JBS diode (D2.1.2)

14

Process Step Value

Epi Thickness 6 µm

Epi Doping 1e16 atm/cm3

Pwell mask 8 µm

PreImplant Oxide Thickness

0.06 µm

Error Dose Factor 1 (nominal Value)

Activation percentage 35%

Schottky Barrier 1.14 eV

Resistance Anode 0.45e-3 Ω*µm

Resistance Schottky 1e-7 Ω*µm

Resistance Cathode 1.1e-3 Ω*µm

Forward and reverse characteristics comparison between measure and simulation.

Calibration of TCAD simulations


CONFIDENTIAL 15

Process variability and DOE setup

15

Variable Description Nominal Min Max Unit

SpSpace among

p-wells8 7.6 8.4 µm

EpiT Epitaxy Thickness 6 5.7 6.3 µm

EpiD Epitaxy Doping 1e16 9e15 1.1e16Atm/cm3

OxT Pre-implant oxide Thickness 0.06 0.054 0.066 µm

errD Dose Error 1 0.9 1.1 -

Att Doping Activation 0.35 0.1 0.6 %

Barrier Schottky Barrier 1.14 1.083 1.197 eV

Rc Cathode Resistance 1.1e-3 9.9e-4 1.21e-3 Ω

Input process parameters that have influence on the device behavior:-FW6 (anode voltage @6A)-FW80 (anode voltage @80A)-BV (breakdown Voltage)-LK600 (leakage current @600V)

Parameters screening

DOE setup in SWB


CONFIDENTIAL 16

Application to AlGaN/GaN HEMTs (D2.1.2)

16

Variable Description Nominal Min Max Units

thAlGaN Thickness of the first AlGaN layer 25 20 30 [nm]

GateFoot Width of the gate foot 0.5 0.4 0.6 [µm]

GatePlate Width of the gate plate 1.3 1.2 1.4 [µm]

Ldg Drain-Gate distance 2.5 2.0 3.0 [µm]

Lsg Source-Gate distance 2.0 1.5 2.5 [µm]

Hgate Height of the gate foot 0.08 0.06 0.1 [µm]

GateRec Erosion of the AlGaN layer under the gate contact 0 0 0.02 [µm]

MolFrac Molar fraction of the first AlGaN layer 0.26 0.24 0.27 --

Schematic cross-section of the AlGaN/GaN HEMT under examination

Input process parameters that have influence on the device behavior:- Id_MAX (maximum drain current value at Vg=2V)- Vth (threshold voltage)- gm (maximum of transconductance for a given Id–Vg)


CONFIDENTIAL 17

Process variability and DOE setup

17

Variable Id_MAX Vth gm

thAlGaN 121.3% 32.9% 76.0%

GateFoot 0.50% 0.69% 1.0%

GatePlate

0.33% 0.32% 1.8%

Ldg 13.2% 0.56% 13.6%

Lsg 16.2% 1.0% 20.0%

Hgate 0.08% 0.05% 2.54%

GateRec 0.99% 87.5% 86.5%

MolFrac 47.4% 12.6% 32.1%

Experiments generated by DoE

Sensitivity analysis


CONFIDENTIAL 18

Conclusions

In D2.1.2 the methodology used to increase TCAD simulation efficiency, by deriving Process Compact Models from systematic well-calibrated simulations, is described.

In order to demonstrate the general concepts of how to use the PCM approach, a 4H-SiC JBS diode and an AlGaN/GaN HEMT device have been investigated. The Synopsys platform (Sentaurus and PCM Studio) has been used.

First the standard cell of the device under examination has been simulated with the nominal values of the process input parameters. Second the process parameters that have an important impact on target electrical parameters have been identified performing a parameter screening. Then, a parameterized simulation setup has been arranged.

To complete the analysis, device simulations have been performed, for each experiment. Moreover post-processing scripts need to be introduced to automatically extract the list of electrical outputs. In this way the RSM model of device characteristics as function of process parameters will be generated by using PCM Studio. Details on this work has been included on D2.2.4.


CONFIDENTIAL 19

T2.1 Back-up slides for AMS and TUW


CONFIDENTIAL 20

Process Variation

• Input Parameters (HV-PMOS)

SX 18 20 22

DN_DOSE 4.05E+012 4.10E+012 4.15E+012

DPOverlay -0.1 0 0.1

SNOverlay -0.1 0 0.1

PADOX_VthM 0.1 10.05 20

Vt_2p7e12 2.65E+012 2.70E+012 2.75E+012

TOXTH -2 0 2

- 143 (7 PV for HV-PMOS) and 272 (8 PV for HV-NMOS) Full Process and Device Simulations


CONFIDENTIAL 21

Process Variation

• Variation Setup (RSM)


CONFIDENTIAL 22

Process Variation

• TCAD Flow

Parameters

SentaurusWork Bench

Minimos

ParameterExtraction

CorrelationInterface between commercial Synopsys Process Simulator and Minimos Device Simulator


CONFIDENTIAL 23

Process Variation

• Minimos Device Simulation• Linked to commercial Synopsys Process Tools• Input from .grd and .dat output of Sentaurus Device• Geometry output of Minimos to .grd and .dat• Characteristics to .crv

• Parameter Extraction• Inhouse Measurement Methods at AMS• extract BSIM Parameters from Simulation• Ron, Vth, Idsat, Sleak, Gamma, Leff


CONFIDENTIAL 24

Process Variation

• Parameter Extraction• Original Matlab Methods at AMS• Rewritten to extract Parameters from Minimos• In Python with SciPy and Numpy• Nearly identical Syntax as in Matlab


CONFIDENTIAL 25

Process Variation

• Vth Extraction


CONFIDENTIAL 26

Process Variation

• Extracted Data


CONFIDENTIAL 27

Process Variation

• Output Parameters <Gamma,Sleak>(SNOverlay)


CONFIDENTIAL 28

Status of PV-aware Process & Device Simulations

• Status

Type Parameters Process Device Parameters

HV-PMOS(20/0.6) finished finished finished finished

HV-PMOS(20/10) finished finished finished finished

HV-NMOS(20/0.7) finished finished finished finished

HV-NMOS(20/10) finished finished finished finished

• Electrical parameter extraction (for Monte Carlo spice model) : done

(Vth_lin, Vth_sat, Idlin, Idsat, Ron, Sleak, Gamma, Leff, …)D2.3.3

*Remarks: HV-PMOS = PMOS20T, HV-NMOS=NMOSI20T


CONFIDENTIAL 29

Quadratic fitting from the simulation results

- H35 technology (0.35 µm HV-CMOS process)

- PMOS20T: 143 structures (7 PV)

- NMOSI20T: 272 structures (8 PV)

TCAD Process & device simulations (sprocess & Minimos-NT)

Quadratic fitting (all PV versus electrical data)

Random 10000 PV-set generation by considering inline PV distributions

Electrical parameter calculation from the quadratic formula

Data analysis


CONFIDENTIAL 30

PMOS20T(20/0.6): Ron and Ron-fit

0 50 100 15011

11.5

12

12.5

13

13.5

14

14.5

15

15.5

16

count

Ron

, R

on-f

it

0 50 100 150-0.3

-0.2

-0.1

0

0.1

0.2

0.3

0.4

0.5

count

Ron

- R

on-f

it


CONFIDENTIAL 31

PMOS20T(20/0.6): Vthlin and Vthlin-fit

0 50 100 1500.5

0.52

0.54

0.56

0.58

0.6

0.62

0.64

0.66

0.68

count

vthl

in,

vtlin

-fit

0 50 100 150-0.025

-0.02

-0.015

-0.01

-0.005

0

0.005

0.01

0.015

0.02

count

vthl

in -

vth

lin-f

it


CONFIDENTIAL 32

PMOS20T(20/0.6): Ron and Vthlin correlation

0.5 0.55 0.6 0.65 0.711

11.5

12

12.5

13

13.5

14

14.5

15

15.5

16

vthlin

Ron

0.5 0.55 0.6 0.65 0.711

11.5

12

12.5

13

13.5

14

14.5

15

15.5

16

vthlin-fit

Ron

-fit


CONFIDENTIAL 33

PMOS20T(20/0.6): 7 PV distributions (10000 random values)

16 18 20 22 240

50

100

150

200

250

300

350

SX

n

4 4.05 4.1 4.15 4.2

x 1012

0

50

100

150

200

250

300

350

400

DN dose

n

-0.2 -0.1 0 0.1 0.20

50

100

150

200

250

300

350

DP overlay

n

-0.2 -0.1 0 0.1 0.20

50

100

150

200

250

300

350

SN overlay

n

-10 0 10 20 300

50

100

150

200

250

300

350

Pad Ox

n

2.6 2.65 2.7 2.75 2.8

x 1012

0

50

100

150

200

250

300

350

Vt implant

n

-4 -2 0 2 40

50

100

150

200

250

300

350

GOX

n


CONFIDENTIAL 34

PMOS20T(20/0.6): Ron and Vthlin distribution

11 12 13 14 150

50

100

150

200

250

300

350

Ron random

n

0.5 0.55 0.6 0.65 0.70

50

100

150

200

250

300

350

400

vthlin random

n


CONFIDENTIAL 35

PMOS20T(20/0.6) & NMOSI20T(20/0.7): Ron versus Vtlin

0.5 0.55 0.6 0.65 0.711

11.5

12

12.5

13

13.5

14

14.5

15

15.5

vthlin random

Ron r

andom

0.39 0.4 0.41 0.42 0.43 0.448.5

9

9.5

10

10.5

11

vthlin random

Ron

ran

dom


CONFIDENTIAL 36

Conclusions

Statistical fab data analysis (FEOL, BEOL) for 0.35µm HV-CMOS Techhnology was done for PV TCAD simulations.

TCAD environment construction: - Process simulator setup & calibration - Critical 7~8 PV selection - Interface development between commercial process simulator and Minimos-NT (a two-dimensional device simulator from TUW) - Script development for electrical parameter extraction

TCAD simulations: - A set of NMOS20T and PMOS20T process and device simulations - NMOS20T and PMOS20T sensitivity analysis - Quadratic curve fitting of simulation results, Random PV generation - PV-aware statistical electrical parameters

T2.1 results (HV-CMOS) T2.3 for Spice Monte-Carlo Model (D2.3.3)


Documents

CONFIDENTIAL WP2 Review Meeting Milan, October 05, 2011 MODERN ENIAC WP2 Meeting (WP2-T2.1) WP2 and Tasks review Milano Agrate, 2011 Oct. 05 Meeting hosted