176
Strain-Engineered MOSFETs
G
P+
P+
n+ Poly gate
Gate oxide 10 Å
Strained Si 135 Å
n-Si (100) Substrate
Si buffer, 0.5 µm
SiGe (18% Ge)
Buffer cap, 0.9 µm
Step-graded (7)
SiGe buffer, 2.1 µm
18% Ge
0% Ge
S
D
FIGURE 6.17
Schematic of a p-MOSFET on pseudomorphic strained Si grown on fully relaxed SiGe buffer
layer. (After Bera, L. K., Studies on Applications of Strained Si for Heterostructure Field-Effect
Transistors (HFETs), PhD thesis, Indian Institute of Technology, Kharagpur, 1998 [38].)
0.00
–0.05
–0.10
–0.15
I
D (mA)
–0.20
–0.25
0
– 1
– 2
V DS (V)
V gs = –4.5 V
V gs = –4 V
V gs = –3 V
V gs = –2 V
V gs = –3.5 V
V gs = –2.5 V
–3
–4
–5
FIGURE 6.18
Typical I d -V d characteristics of a p-MOSFET with pseudomorphic strained Si grown on a fully
relaxed SiGe buffer layer of dimension L/W = 300 μm/100 μm (strained Si on an 18% Ge buffer layer).
Strain-Engineered MOSFETs
G
P+
P+
n+ Poly gate
Gate oxide 10 Å
Strained Si 135 Å
n-Si (100) Substrate
Si buffer, 0.5 µm
SiGe (18% Ge)
Buffer cap, 0.9 µm
Step-graded (7)
SiGe buffer, 2.1 µm
18% Ge
0% Ge
S
D
FIGURE 6.17
Schematic of a p-MOSFET on pseudomorphic strained Si grown on fully relaxed SiGe buffer
layer. (After Bera, L. K., Studies on Applications of Strained Si for Heterostructure Field-Effect
Transistors (HFETs), PhD thesis, Indian Institute of Technology, Kharagpur, 1998 [38].)
0.00
–0.05
–0.10
–0.15
I
D (mA)
–0.20
–0.25
0
– 1
– 2
V DS (V)
V gs = –4.5 V
V gs = –4 V
V gs = –3 V
V gs = –2 V
V gs = –3.5 V
V gs = –2.5 V
–3
–4
–5
FIGURE 6.18
Typical I d -V d characteristics of a p-MOSFET with pseudomorphic strained Si grown on a fully
relaxed SiGe buffer layer of dimension L/W = 300 μm/100 μm (strained Si on an 18% Ge buffer layer).