US4969116A
Expired / Lapsed
US
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Method of generating discretization grid for finite-difference simulation
Assignee: Toshiba Corp
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Filing: 1988-09-28
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Granted: 1990-11-06
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Expires: 2008-09-28
Abstract
Abstract A method of generating a discretization grid for a finite-difference simulation capable of simulating an object with a complex cross-sectional configuration accurately is disclosed. The method includes the step of generating grid through each vertex of the polygonal figure representing the cross-sectional configuration, and the step of generating additional grid through each intersection of the grid and the segments of the polygonal figure not parallel to the grid.
Inventors
- 👤 Tetsunori Wada
- 👤 Shinji Oosawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 13:24
CPC Classifications
G; G06; G06F; G06F30/00; G06F30/20; G06F30/23
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
109 words
A method of evaluating the characteristics of a semiconductor device, comprising the steps of: (a) representing a cross section of the semiconductor device by a polygonal figure; (b) generating rectangular grids to locate one grid intersection point over each vertex of the polygonal figure; (c) generating additional rectangular grids in order to locate one grid point over each intersection of rectangular grids generated at step (b) and segments of the polygonal figure which are not parallel to lines of the rectangular grids generated at step (b); and (d) evaluating the characteristics of the semiconductor device on the grid points of the rectangular grids generated at steps (b) and (c).
Claim 2
Independent Claim
109 words
A method of evaluating the characteristics of a semiconductor device, comprising the steps of: (a) representing a cross section of the semiconductor device by a polygonal figure; (b) generating rectangular grids to locate one grid intersection point over each vertex of the polygonal figure; (c) generating additional rectangular grids in order to locate one grid point over each intersection of rectangular grids generated at step (b) and segments of the polygonal figure which are not parallel to lines of the rectangular grids generated at step (b); and (d) evaluating the characteristics of the semiconductor device on the grid points of the rectangular grids generated at steps (b) and (c).
Claim 3
Dependent Claim
118 words
The method of claim 1, further comprising the step of: (e) generating additional rectangular grids to locate one grid point over each intersection of the rectangular grids generated at step (c) and the segments of the polygonal figure which are not parallel to lines of the rectangular grids generated at the step (c), as well as to locate one grid point over each intersection of the rectangular grids generated at this step and the segments of the polygonal figure which are not parallel to lines of the rectangular grids generated at this step; wherein at step (d) the characteristics of the semiconductor device are also evaluated on the grid points of the rectangular grids generated at step (c).
Claim 4
Dependent Claim
54 words
The method of claim 2, further comprising the step of: (f) generating additional rectangular grids in a vicinity of boundaries between different materials contained in the semiconductor device; wherein at step (d) the characteristics of the semiconductor device are also evaluated on the grid points of the rectangular grids generated at the step (f).
Claim 5
Dependent Claim
77 words
The method of claim 3, further comprising the steps of: (g) generating additional rectangular grids to locate one grid point over each intersection of the rectangular grids generated at step (f) and the segments of the polygonal figure which are not parallel to lines of the rectangular grids generated at step (f); wherein at step (d) the characteristics of the semiconductor device are also evaluated on the grid points of the rectangular grids generated at step (g).
Claim 6
Dependent Claim
118 words
The claim of claim 4, further comprising the step of: (h) generating additional rectangular grids to locate one grid point over each intersection of the rectangular grids generated at step (g) and the segments of the polygonal figure which are not parallel to lines of the rectangular grids generated at step (g), as well as to locate one grid point over each intersection of the rectangular grids generated at this step and the segments of the polygonal figure which are not parallel to lines of the rectangular grids generated at this step; and wherein at step (d) the characteristics of the semiconductor device are also evaluated on the grid points of the rectangular grids generated at step (h).
Claim 7
Dependent Claim
75 words
The method of claim 1, further comprising the step of: (i) generating additional rectangular grids such that each separation between adjacent lines of the rectangular grids generated at steps (b), (c) and this step has a ratio not greater than a prescribed value with respect to an adjacent separation; and wherein at step (d) the characteristics of the semiconductor device are also evaluated on the grid points of the rectangular grids generated at step (i).
Claim 8
Dependent Claim
77 words
The method of claim 6, further comprising the step of: (j) generating additional rectangular grids to locate one grid point over each intersection of the rectangular grids generated at stop (i) and the segments of the polygonal figure which are not parallel to lines of the rectangular grids generated at step (i); wherein at step (d) the characteristics of the semiconductor device are also evaluated on the grid points of the rectangular grids generated at step (j).
Claim 9
Dependent Claim
117 words
The method of claim 7, further comprising the step of: (k) generating additional rectangular grids to locate one grid point over each intersection of the rectangular grids generating at step (j) and the segments of the polygonal figure which are not parallel to lines of the rectangular grids generated at step (j), as well as to locate one grid point over each intersection of the rectangular grids generated at this step and the segments of the polygonal figure which are not parallel to lines of the rectangular grids generated at this step; wherein at step (d) the characteristics of the semiconductor device are also evaluated on the grid points of the rectangular grids generated at step (k).
Claim 10
Dependent Claim
94 words
The method of claim 1, further comprising the steps of: (1) calculating, for each pair of adjacent grid points, a quantity related to the physical properties of the semiconductor device; and (m) generating additional rectangular grids in regions where the quantity calculated at step (1) varies from one pair of adjacent grid points to an adjacent pair of adjacent grid points by a value greater than a prescribed value; wherein at step (d) the characteristics of the semiconductor device are also evaluated on the grid points of the rectangular grids generated at step (m).
Claim 11
Dependent Claim
77 words
The method of claim 9, further comprising the step of: (n) generating additional rectangular grids to locate one grid point over each intersection of the rectangular grids generated at step (m) and the segments of the polygonal figure which are not parallel to lines of the rectangular grids generated at step (m); wherein at step (d) the characteristics of the semiconductor device are also evaluated on the grid points of the rectangular grids generated at step (n).
Claim 12
Dependent Claim
117 words
The method of claim 10, further comprising the step: (o) generating additional rectangular grids to locate one grid point over each intersection of the rectangular grids generated at step (n) and the segments of the polygonal figure which are not parallel to lines of the rectangular grids generated at step (n), as well as to locate one grid point over each intersection of the rectangular grids generated at this step and the segments of the polygonal figure which are not parallel to lines of the rectangular grids generated at this step; and wherein at step (d) the characteristics of the semiconductor device are also evaluated on the grid points of the rectangular grids generated at step (o).
Claim 13
Dependent Claim
32 words
The method of claim 1, wherein at step (d) the grid points are represented by their coordinates with respect to a prescribed coordinated system in evaluating the characteristics of the semiconductor device.
Claim 14
Dependent Claim
43 words
The method of claim 12, wherein at step (d) all overlapping coordinates among the coordinates representing the grid points are removed, and all remaining coordinates representing the grid points are rearranged in a prescribed order after all of the overlapping coordinates are removed.
Claim 15
Dependent Claim
37 words
The method of claim 3, wherein at step (f) the boundaries between different materials contained in the semiconductor device are determined in accordance with material data containing information of the different materials contained in the semiconductor device.
Claim 16
Dependent Claim
58 words
The method of claim 11, wherein at step (i) the additional rectangular grids are generated such that one grid point is located on a mid-point of each separation between adjacent lines of the rectangular grids generated at the steps (b), (c) and (i), which as a ratio greater than a prescribed value with respect to an adjacent separation.
Claim 17
Dependent Claim
30 words
The method of claim 13, wherein two of the coordinates representing the grid points are considered overlapping when a distance between these two coordinates is less than a prescribed value.
Claim 18
Dependent Claim
42 words
The method of claim 1, wherein at step (d) the characteristics of the semiconductor device are evaluated on a basis of partial differential equations which are discretized by using the grid points of the rectangular grids generated at steps (b) and (c).
Claim 19
Dependent Claim
26 words
The method of claim 3, wherein at step (f) the different materials are the semiconductor and conductive materials of the semiconductor device proximate to each other.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1993-11-05 | 1994-05-07 | 1994-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-11-05 | 1998-05-07 | 1998-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-11-05 | 2002-05-07 | 2002-11-06 | $7700.00 | Window Closed / Lapsed |