PCM测试图形介绍

2, Contact chain PCM name: XXX A*B Rc (A size; B contact number) Test method: force I, measure V, Rc=V/I/B
1
2
3
4
V
Kelvin Contact
Contact Chain
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Threshold Voltage
PCM Introduction
XuBQ 2010-09-09
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Process Control Monitor (PCM) = Wafer Acceptance Test (WAT) = Electrical Test (E-test)
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PCM工序的作用
监控在线工艺对电参数的影响，以及工艺的波动； PCM一般判定规则:
Ids = 1 μCox(W )(Vgs − Vth)2
2
L
Gm2 = ∂ Ids ∂Vgs
影响因素：
9 沟道注入异常导致开启电压失效； 9 注入损伤或刻蚀损伤在退火过程中没有消除； 9 衬底的浓度异常或阱注入异常； 9 栅氧化层的厚度异常； 9 沟道的长度异常（对于沟长较短的管子影响比较明
显）；
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Contact: R CONT, Reliability
D1, reflow: M1 COMB, MEAND M1-G FOX, M1/PLY CAP
S/D: N+/P+ R, BV Cont R
LDD/SPACER: MOS Ion MOS BV FOX punch through
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D2: M2/M1 CAP VIA
Contact resistance ¾ S/D-metal, silicide-metal, S/D-silicide, poly-metal, metal-metal, etc.
Capacitance
Intra-layer capacitance ¾ Poly-poly, metal-metal
Vth(lin), Vth(sat), Gm(lin), Id(sat), Swing, Ig, BVd/sgt, BVsd/gt, BVsdg/t
BJT
Hfe, Va, Bvceo, Bvcbo, Bvebo
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PCM测试常用模块介绍
NXSTRW（N管参数） PXSTRW（P管参数） NPLUS（N+RES，Rc） PPLUS（P+RES，Rc）
Thin dielectric leakage ¾Gate oxide, tunneling oxide, capacitor dielectric
Intra/inter –line leakage ¾ILD/IMD leakage, dielectric interface leakage
MOSFET
SMU Source Measurement Unit; VMU Voltage Measurement Unit; VSU Voltage Source Unit; PGU Pulse Generate Unit;
GND Force
Guard
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测试程序运作过程
RUN START LOAD PROG 选择测试文件
影响因素：
9 衬底浓度太浓会造成单结击穿电压偏小； 9 沟效应会造成源漏串通电压偏小； 9 栅氧的质量也会影响击穿电压的值；
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Saturation current
PCM name: Ids(sat) Test method: Vs=Vb=Gnd, Vg=Vd=Vdd, Measure Ids
测试循环
检查硬件
Master.6bc TESTSUBS.6
根据输入产品信息， 自动选择WAFER文件； TESTS.6；ALGS.4072； TSTLST；测试项
结束测试
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CMOS简易流程
NW/PW Active FOX(IMP, FOX) VT IMP GOX POLY
M1 Contact D1, reflow
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Sheet Resistance
1, Van Der Pauw (be not affected by ΔW )
PCM name: XXX SHEET RES
Test method: force I, measure V, Res=4.532*V/I
2, Line structure resistor (2-term, 4-term kelvin) (can be affected by ΔW )
Breakdown Voltage
PCM name: (1) Bvd/sgt, (2) Bvsd/gt, (3) Bvsdg/t Test method: for Bvd/sgt, sweep Vds, Vs=Vg=Vb=Gnd, Measure Ids BVd/sgt=Vds@Ids=1uA
V
GATE
显）；
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Threshold Voltage
3, Threshold Voltage in saturation region (Max gm2)
PCM name: Vth(sat)
Test method: Vds=Vgs, Vs=Vb=Gnd, sweep Vgs and measure Ids, get the gm, and get the intercept of Vgs axis as Vth.
W .T T W
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3
4
A
B
Line Structure
Contact Resistance
1, Single window KELVIN contact (should be L shape) PCM name: XXX Cont RES Test method: force I, measure V, Rc=V/I
L
Gm = ∂Ids = μCox(W )Vds
∂Vgs
L
Vth = Vgs @ gmmax − 0.5
|0.1V|
G
D
S SUB
WELL
接地
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Threshold Voltage
2, Threshold Voltage in linear region ( Ids approximation) PCM name: Vth(lin) Test method: Vds=0.1V, Vs=Vb=Gnd, Sweep Vgs, Measure Id,
Ids 5.0E-04 4.0E-04
N 20/20 Id y = 5E-05x2 - 4E-05x + 4E-06
3.0E-04
2.0E-04
Ids = 1 μ Cox ( W )( Vgs − Vth ) 2
2
L
Vdd
G
D
S
SUB
接地
影响因素：
9 衬底浓度的高低与Ion存在反比的关系； 9 短沟时Ion 会偏大； 9 栅氧偏薄会造成Ion 偏大； 9 对于有沟注的产品，沟注剂量大小也会影响Ion的值；
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Ids-Vgs / Ids-Vds curve
S/D SPACER
LDD
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D2 VIA M2 Passivation Alloy END
CMOS简易流程中的重要参数
WELL: R, BV
Active/Field: Vtf, junction BV
VT IMP: MOS VT
GOX: Tox, BV
POLY: R, Leff
M1: M1 SHEET R M1 COM/MND
1, Threshold Voltage in linear region (Max gm) PCM name: Vth(lin) Test method: Vds=0.1V, Vs=Vb=Gnd, Sweep Vgs, Measure Id, Get the Gm
Ids = μCox(W )(Vgs −Vth − 0.5Vds).Vds
Eg. 1# low, other 2 ok, D to S have leakage 2# low, other 2 ok, S to G have leakage 3# low, other 2 ok, G to SUB have leakage ……
A comment is, because BV test can damage device, we need analyze together with other data.
Interconnect isolation ¾Poly-poly, metal-metal
Continuity
Active aream poly-si, silicide area, metal-line, etc.
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Key PCM Group -III
Leakage
Junction leakage ¾Bulk, AA edge, spacer edge, small silicide area
Get the Vgs@Ids=1uA
Ids = 1 μCox (W )(Vgs − Vth)2
2
L
Vth =素：
9 沟道注入异常导致开启电压失效； 9 注入损伤或刻蚀损伤在退火过程中没有消除； 9 衬底的浓度异常或阱注入异常； 9 栅氧化层的厚度异常； 9 沟道的长度异常（对于沟长较短的管子影响比较明
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Hardware structure(AG-4072/prober)
外置测试仪 4284/3458/8110
HP-UX 工作站
CPU
GPIB
光纤
SMU GNDU
SWM
探针卡
TEST HEAD
探针台
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Tester 基本部分
包括I-V、C-V两类
¾ IV：SMU、VSU、VMU、PGU； ¾ CV：4280/4284； ¾ 以及万用表3457/3458;
（1）根据PCM checklist，形成一个PCM summary测试参数组； （2）每片圆片通常都会测试(上中下左右）5个位置； （3）任何参数项的5个数据，失效数>=3，则该圆片的PCM参数失效则该 wafer失效； （4）否则，该wafer的PCM参数pass；
判定wafer Pass/Fail的一个重要依据，客户会根据PCM测试情 况，决定接收、拒收还是有条件接收wafer。
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PCM测试常用模块介绍
TUBS(NTUB VDP, Via chain）
CAPNP （NGOX,PGOX)
PTRANW2 (Via stitch)
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M1LSVDP (M1 VDP)
PCM测试常用模块介绍
PGT(POLY VDP, Cont Res)
CAPPC （Inter-Poly Cap)
VIA: VIA R, reliability
M2: M2 SHEET R M2 COM/MND Passivation:
Alloy: MOS VT
END
Key PCM Group -I
Resistance
Sheet resistance ¾ N-well, P-well, n-LDD, p-LDD, n-S/D, p-S/D, n-poly gate, p-poly gate, silicide region, metal, etc.
Inter-layer capacitance ¾ G-channel, G-S/D, G-ISO, M-G,M-sub, M-M, etc.
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Key PCM Group -II
Isolation
Device isolation ¾ Intra-well isolation, inter-well isolation
D
S
SUB
接地
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Breakdown Voltage
Always test 3 BV for a device: 1#, BVd/sgt; 2#, BVsd/gt; 3#, BVt/sdg
Test 3 BV, is helpful to find out the root reason directly from PCM data.
PCM name: XXX L/W RESK (if Kelvin, add K) Test method: KELVIN, force I, measure V, R=V/I
3
V
2-term, directly measure R
2
4
1
Van Der Pauw
R = ρ.
L
=
ρ
.
L
=
Rs.square