semi合集-English.pdf - 第5454页

SEMI M61-0705 © SEMI 2005 3 ITEM SPECIFICATION 6 Requirements 6.1 General Characteristics 6.1.1 The epitaxial wafers with buried layers shall meet al l requirements specified in the purchase order including those requi r…

100%1 / 7923
SEMI M61-0705 © SEMI 2005 2
4.2.2 buried layer — a diffused region in a substrate that is, or is intended to be, covered with an epitaxial layer.
4.2.3 pattern distortion ratio — absolute magnitude of the quotient of (1) the difference between the width of the
pattern on the substrate and the width of the pattern on the top surface of the epitaxial layer and (2) the thickness of
the epitaxial layer.
4.2.4 pattern shift ratio — lateral distance between the center point of the pattern on the surface of the substrate and
the center point of the pattern on the surface of the epitaxial layer divided by the epitaxial layer thickness.
4.2.5 pattern step height — difference in vertical position of the diffused (buried layer) surface and the original
substrate surface, after removal of oxide.
5 Ordering Information
5.1 Purchase orders for silicon epitaxial wafers furnished to this specification shall include the items indicated in
sections 4-1 through 4-3 of Part 4 of the Specification Format for Order Entry (for Epitaxial Wafer with Buried
Layer) shown in Table 1. Other specified characteristics, as required, may be added in section 4-4 of the format.
5.2 In addition, the purchase order shall include
the material in Part 1 (General Information) of the Specification Format for Order Entry, in SEMI M1,
specifications for the substrate wafer of the appropriate characteristics as defined in Part 2 (Polished Wafer or
Substrate) also in SEMI M1, and
specifications for the epitaxial layer as defined in SEMI M2.
NOTE 1: Note that the orientation of single crystal is differently specified in SEMI MF26 and JEITA EM-3501.
5.3 The following items must also be included in the purchase order:
5.3.1 Lot acceptance procedures.
5.3.2 Certification (if required).
5.3.3 Packing and marking requirements.
Table 1 Specification Format for Order Entry
Part 4 Epitaxial Wafer with Buried Layer
ITEM SPECIFICATION
1. PHOTOLITHOGRAPHY CHARACTERISTICS
4-1.1 Mask ID [ ] Number: [ ]; [ ]None
4-1.2 Alignment Precision X max [ ] µm, Y max [ ] µm;
Reference Point (Wafer Coordinate System): x [ ] mm, y [ ] mm;
max [ ]
4-1.3 Pattern Line Width Tolerance Tolerance ± [ ] µm
2. BURIED LAYER CHARACTERISTICS
4-2.1 Dopant [ ]B; [ ]P; [ ]Sb; [ ]As
4-2.2 Diffusion Depth (x
j
) Nominal [ ] ± Tolerance [ ] µm
4-2.3 Sheet Resistance Nominal [ ] ± Tolerance [ ] /sq
4-2.4 Pattern Step Height Nominal [ ] ± Tolerance [ ] nm
4-2.5 Defect Density (Before Epi) Not greater than [ ]/cm
2
3. BURIED LAYER PATTERN CHARACTERISTICS AFTER EPI
4-3.1 Pattern Shift Ratio Nominal [ ] ± Tolerance [ ]
4-3.2 Pattern Distortion Ratio Max. [ ]
4. OTHER CHARACTERISTICS
SEMI M61-0705 © SEMI 2005 3
ITEM SPECIFICATION
6 Requirements
6.1 General Characteristics
6.1.1 The epitaxial wafers with buried layers shall meet all requirements specified in the purchase order including
those requirements related to both the substrate wafer and epitaxial layer properties.
6.2 Photolithography Characteristics
6.2.1 The identified mask shall be used in making the pattern for the diffused layers.
6.2.2 The alignment precision shall meet the specified requirements as follows:
6.2.2.1 The values of X and Y, the displacement of the center of the pattern from a reference position defined in the
wafer specification in terms of the wafer coordinate system defined in SEMI M20, shall not exceed the maximum
values specified.
6.2.2.2 The value of θ, the angle between the x-axis of the pattern and the primary orientation flat (see Figure 1)
shall not exceed the maximum value specified.
6.2.3 The pattern line widths (see Figure 2) shall be within the specified tolerance of the desired values.
6.3 Buried Layer Characteristics
6.3.1 The dopant shall be the element specified: boron (B), phosphorus (P), antimony (Sb) or arsenic (As).
6.3.2 The diffusion depth shall fall within the tolerance of the nominal value specified in micrometers (m).
6.3.3 The sheet resistance of the diffused layer shall fall within the tolerance of the value specified in ohms per
square (/sq).
Figure 1
First Mask Showing Angular Displacement
Figure 2
Schematic Diagram Showing Line Width, A, of Pattern on Substrate Wafer
SEMI M61-0705 © SEMI 2005 4
6.3.4 The pattern step height A as shown in Figure 3, shall meet the nominal value X within the tolerance Y, as
specified in nanometers (nm).
Figure 3
Cross-Sectional View of Epitaxial Substrate After Oxide Removal but Before Deposition of the Epitaxial Layer
Showing the Pattern Step Height, A
6.3.5 The defect density on the surface after deposition but before growth of the epitaxial layer shall not exceed the
density specified in number of defects per square centimeter.
6.4 Buried Layer Pattern Characteristics after Growth of the Epitaxial Layer
6.4.1 The pattern shift ratio d/t (see Figure 4) shall meet the specified requirements for nominal value X and
tolerance ±Y, both of which are dimensionless because both d and t are in micrometers (µm).
Figure 4
Cross-Section View of Epitaxial Wafer Showing the Pattern Shift, d.
Not to scale: AM = MB and CN = ND
6.4.2 The pattern distortion ratio shall not exceed the maximum value specified. This dimensionless ratio is equal
to
t
ba
ratio distortionpattern (1)
where:
a = width of pattern on epitaxial layer,
b = width of pattern on substrate, and
t = thickness of epitaxial layer
as shown in Figure 5
Figure 5
Cross-Section View of Epitaxial Layer Showing the Pattern Widths, a,
at the Epi Surface, and b, at the Layer-Substrate Interface