When activated undoes the previous command. If a process has been defined, this item, when selected, unselects the process. In the latter case its name is changed to "Unselect Process".
2. "Cut"
3. "Copy"
4. "Paste"
5. "Clear"
6. "Select All"
All these commands are only used in connection with text editing.
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7. The "Color" command:
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Its selection causes the appearance of a standard color selection pallette. The same effect is achieved by using the following shortcut: Click over a region while keeping the "Option" key pressed!
N.B. Clicking the mouse once anywhere over a given region causes the latter to be selected (outlined). This also activates the "Color" and the "Material’s Data" commands, as well as the "Remove..." command from the "Process" menu (see the "Process" menu).
This item is only enabled when a region has been selected (normally by a single click over the region). When enabled, this item automatically changes to “Data for ‘name’”, where ‘name’ is the material’s name of the region selected. The selection of this command causes the appearance of a dialog box, where material specific information (such as material name, color and etch rate data can be specified. The same effect is achieved by using the following shortcut: Double click anywhere over a region of a given material (see "Etching" in the Process Menu).
In the dialog box:
The name of the material is written directly in the name field. The control button "Material's Name" located to the left of the name field is for future versions and is used here to specify the location of the name field.
N.B. Various data items may not be changed during various stages of simulation. Thus for instance, the name of a material can only be specified if no process has been selected. (To unselect a process use the "Undo" command above). Conversely, material specific etch rate information can only be specified if an "Etching" process has been selected.
Assuming that the user has defined an "Etching" process (see "Etching" in the Process Menu) he/she may fill in the following three fields if enabled (the use of radio buttons here does NOT mean that the fields are mutually exclusive!):
a) Isotropic:
Specify the etch rate if there is an isotropic erosion component for that specific material.
b) Directional:
Specify the etch rate (or rather a coefficient) and specify a file containing the angular dependence of the etch rate for that particular material via the "Select(ed) file for angular dependence" file selection button in the lower left corner of the dialog box. Remember that the erosion data in the file selected is multiplied by the above coefficient. (This coefficient is provided for greater freedom - inclusion of synergistic effects, etc.). It is also recalled that the angle of incidence of the incident flux and its divergence have already been defined in the "Etching" dialog box (see the "Etching" command in the Process menu), since these are common for all materials.
It is important to note that the etch rate (coefficient) one specifies is the one which corresponds to zero divergence, that is, this would be the etch rate corresponding to a fully collimated flux J. Specifying a non-zero divergence is equivalent to angularly spreading the incident erosion flux in a uniform fashion in an angular range which is equal to twice the divergence (for further discusion see 'To Remember'). In other words the integral of the incident flux over the angular range is exactly equal to J. (Think of an initially collimated flux which is uniformly defocused in the given angular range).
The etch rate data in the "Select(ed) file for angular dependence" must cover the angular range between 0 and 90 degrees (see I/O Formats). The angular dependence is assumed to be a function of the angle of incidence to the surface only, i.e. the angle between the surface normal and the incidence direction.
(To unselect a file, containing the angular dependence of the etch rate, press the "Option" key and click over the file selection button.)
c) Anisotropic:
Specify the etchrate (or rather a coefficient) and specify a file containing the angular dependence of the etch rate for the particular material via the "Select(ed) file for angular dependence" button in the lower left corner of the dialog box (the same button as above). Remember that the erosion data in the file selected is multiplied by the above coefficient. (This coefficient is provided for greater freedom - inclusion of synergistic effects, etc.).
The etch rate data in the "Selected file for angular dependence" must cover the angular range between 0 and 360 degrees (see I/O Formats). The 0 degree coincides with the vertical direction of the structure, i.e. a horizontal surface with its normal pointing up.
(To unselect a file, containing the angular dependence of the etch rate, press the "Option" key and click over the file selection button.)
Note that only those fields from the above three will be enabled which correspond to the fundamental etch types selected in the "Etching" dialog box (see "Etching" in the Process Menu).
N.B. The use of radio buttons here is introduced to uniquely define the two files containing the angular dependences for the "Directional" and "Anisotropic" processes respectively, since the same file selection button ("Select(ed) file for angular dependence") is used in both cases.
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9. The "Preferences" command:
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Opens the Preferences dialog box. It provides the following options:
a) Interpolation:
The angular dependence data for various etching and deposition processes, provided by the user, are interpolated by the program for rate determination at intermediate points. One can choose between a LINEAR and a CUBIC SPLINE interpolation procedures.
b) Simulation:
One of the main inputs required by the user is the definition of the initial structure. This structure is normally defined in a text file according to a specific format (see I/O Formats). Experience shows that the user most frequently uses one and the same initial structure to begin with, for instance a plain Si wafer. For this purpose and to bypass the file selection dialog, a default file named "InitialStructure" and located in the same folder as the program itself, is used for structure definition when the "New" command from the "Simulation" menu is selected. In other words, if the user checks the "Template" button in the "Preferences" dialog box, the above "New" command will attempt to locate the default file "InitialStructure", read in the structure and if successful display the latter graphically in a window.
Checking the "File" button on the other hand will cause the appearance of a standard "Open file dialog box" when the user selects the "New" command from the Simulation menu, giving the user the possibility to select any text file which contains the definition of the desired initial structure.
c) Time Unit:
The user can choose between the given time units for the processes simulated. This option is disabled when a process has been selected. Unselect the current process if you wish to change the time unit. (See the "Undo" command in the Edit Menu).
d) Spatial Unit:
Similar to the previous one. It is always disabled after the first process has been completed or if an old simulation is opened via the "Open" command.
The spatial and temporal units are common for all type of data specified by the user. Thus, the Initial Structure units and the erosion or deposition rates use the same spatial units, which are identical to the unit selected in the Preferences dialog box!
The temporal unit may be varied between processes!
N.B. See 'Memory and Speed Considerations' in the "To Remember!" help file.
e) Window size:
Shows the current window dimensions in screen pixels. This is the default window size if the window has not been resized after a "Fit to window" command (see the Simulation Menu). The latter command is automatically executed when a new Process window is first opened. In the latter case the default dimensions are equal to the default global dimensions in the "Global Preferences" dialog box( see below). If a Process window is opened via the "Open" command (see the File Menu) then it is opened with its default window size at the time when it was last saved.
The following conventions are used:
*) if any of the values specified is larger than the current screen size, it is defaulted to the maximum possible value for that particular screen size.
**) a minimum pixel size of 100 is used as default.
***) to restore a window's default size (after having resized it) specify a negative value in any of the fields (see the "Fit to window" command in the Simulation Menu for a default size).
N.B. There are two types of preferences: one which is global or general and another which is window specific. If the front most window is a Process window, opening the Preferences dialog refers to the window specific type. That is, all changes are private for the front most window and have no effect on other windows or default (global) values. The Preferences dialog title at the top of the box reads: "Preferences for window: ...".
If the front most window is not a Process window then the Preferences dialog title at the top of the box reads: "General Preferences". All changes in this box are marked as global and new windows will copy these values, unless the user opens an old file.
If the front most window is a Process window and you wish to select the General Preferences box, press the "Option" key before selecting the "Preferences" command.
Copyright 1996 I.V.Katardjiev. All rights reserved.
