KR100598477B1 - Microelectronic substrate having conductive material with blunt cornered apertures, and associated methods for removing conductive material - Google Patents

Abstract

The present invention relates to a microelectronic substrate and a method for removing a conductive material from the microelectronic substrate. In one embodiment, the microelectronic substrate comprises a conductive material or semiconductor material having recesses with initially sharp corners on the surface of the conductive material. The corner may be blunted or rounded, for example, by applying a voltage to an electrode in fluid communication with an electrolyte fluid disposed adjacent to the corner. The current flowing from the electrode through the corner can oxidize the conductive material at the corner, which can be removed by a chemical etching process.

Microelectronic Substrates, Electrolyte Fluids, Conductive Materials, Electrodes, Etching

Description

Microelectronic substrate having conductive material with blunt cornered apertures, and associated methods for removing conductive material

Related Applications
This application is filed on August 30, 2000, entitled " Methods and Apparatus for Removing Conductive Material From a Microelectronic Substrate, " US Application No. 09 / 651,779 (Attorney Docket No. 108298515US), 6, 2001. United States Application No. 09 / 888,084 filed on May 21, entitled "Methods and Apparatus for Electrical, Mechanical and / or Chemical Removal of Conductive Material From a Microelectronic Substrate" (Representative Document No. 108298515US1), 2001 Partial series of U.S. Application No. 09 / 888,002 (Attorney Docket No. 108298515US3), filed June 21 and entitled "Methods and Apparatus for Electrically and / or Chemically-Mechanically Removing Conductive Material From a Microelectronic Substrate" All of which are incorporated herein by reference in their entirety.
Technical field
The present invention relates to methods and apparatus for removing conductive and / or semiconductor materials from microelectronic substrates.

Microelectronic substrates and substrate assemblies typically include a semiconductor material having portions such as transistors and transistor gates connected to conductive lines. One conventional method for forming transistor gates (shown schematically in FIGS. 1A-1C) is shallow trench isolation (STI). First, in FIG. 1A, an STI process typically includes doping the semiconductor substrate 10 to at least partially form the conductive material 11. The oxide layer 14 is disposed on the conductive material 11, and the nitride layer 15 is disposed on the oxide layer 14. A mask 16 having a mask opening 17 is then disposed with respect to the oxide layer 14 and the semiconductor substrate 10 is etched to form the gap 60 shown in FIG. 1B. As shown in FIG. 1C, the gap 60 is coated with a gate oxide layer 61, and the gate material 62 is disposed adjacent to the gate oxide 61. Thus, the gate oxide 61 may be electrically insulated from the adjacent gate. The nitride layer 14 and the oxide layer 15 can then be removed.

One disadvantage with the STI structure described above in conjunction with FIGS. 1A-C is that the conductive material 11 has sharp corners 63 (shown in FIGS. 1B and 1C) at the edge of the gap 60. The sharp corners 63 may emit electromagnetic radiation (generally in an antenna manner) that may interfere with the operation of adjacent semiconductor portions. One conventional approach to the above-mentioned disadvantage is to oxidize the material of the sharp corner 63 by exposing the semiconductor substrate 10 to a high temperature environment (ie, about 1050 ° C.). The oxidized material is then removed to blunt the corners. One drawback to this approach is that the curvature that can be achieved at high temperatures can be limited. Another disadvantage is that high temperatures can damage parts or components of the semiconductor substrate. Another disadvantage is that high temperature processing is expensive, which can increase the cost of the article formed from the semiconductor substrate.

One prior art for removing bulky conductive material from a semiconductor substrate includes applying alternating current to the conductive layer through an intermediate electrolyte to remove a portion of the conductive layer. In one configuration shown in FIG. 2A, the prior art device 60 includes a first electrode 20a and a second electrode 20b connected to a power source 21. The first electrode 20a is attached directly to the metal layer 11a of the semiconductor substrate 10 and the second electrode 20b is moved downward until the second electrode 20b is in contact with the electrolyte 31, thereby the metal layer 11a. It is at least partially submerged in the liquid electrolyte 31 placed on the surface thereof. The barrier 22 prevents the first electrode 20a from making direct contact with the electrolyte 31. The power source 21 applies an alternating current to the substrate through the first electrode 20a and the second electrode 20b to remove the conductive material from the conductive layer 11a. The alternating signal is a waveform of the invention entitled "Electroetching of Platinum in Titanium-Platinum-Gold Metallization in Silicon Integrated Circuits" (Bell Laboratories) and published by Mr. Frankenthal et al., Incorporated herein by reference in its entirety. Can have

One disadvantage of the device shown in FIG. 2A is that barrier 22 prevents electrolyte 31 from contacting the substrate in the region to which first electrode 20a is attached, thereby preventing the material from conductive layer 11a in that region. It cannot be removed. Alternatively, if the first electrode 20a is in contact with the electrolyte in the region, the electrolyte process may deteriorate the quality of the first electrode 20a. Another disadvantage is that the electrolyte process cannot uniformly remove material from the semiconductor substrate 10. For example, an "island" of residual conductive material that is not directly electrically connected to the first electrode 20a may be developed in the conductive layer 11a. Residual conductive material may interfere with the formation and / or operation of conductive lines and may be difficult or impossible to remove in an electrolyte process unless the first electrode 20a is repositioned to couple to the “island”. have.

An approach to some of the above disadvantages described above is to attach a plurality of first electrodes 20a around the periphery of the semiconductor substrate 10 to increase the uniformity in which the conductive material is removed. However, the island of conductive material remains despite the additional first electrode 20a. Another approach is to form the electrodes 20a and 20b with an inert material such as carbon and remove the barrier 22 to increase the area of the conductive layer 11a in contact with the electrolyte 31. However, the inactive electrodes are not as effective as the reactive electrode when removing the conductive material, and the inactive electrodes can leave the remaining conductive material on the semiconductor substrate 10.

FIG. 2B illustrates an approach to some of the aforementioned disadvantages in which two semiconductor substrates 10 are partially contained in a vessel 30 containing an electrolyte 31. The first electrode 20a is attached to one substrate 10 and the second electrode 20b is attached to the other substrate 10. The advantage of this approach is that the electrodes 20a and 20b are not in contact with the electrolyte. However, islands of conductive material still remain after the electrolyte process is complete, and it may be difficult to remove the conductive material at the point where electrodes 20a and 20b are attached to semiconductor substrate 10.

The present invention relates to a microelectronic substrate comprising a conductive material having a recess with rounded corners and a method of forming such a microelectronic substrate. The method according to one aspect of the invention includes disposing an electrolyte fluid adjacent a conductive material of a microelectronic substrate. The conductive material has a first surface of a first plane and a recess of the first surface, the recess being bounded by a second surface of the second plane. The conductive material further has a corner between the first surface and the second surfaces. The method also includes removing at least a portion of the conductive material from the corner by placing the first electrode and the second electrode in fluid communication with the electrolyte fluid, and coupling at least one of the electrodes to the front panel. The process of removing the conductive material from the corner may self limit depending on the rate at which the conductive material is reduced when the corner is rounded.

In another aspect of the invention, a method for forming a microelectronic substrate includes disposing a common nonconductor material adjacent to a conductive material of the microelectronic substrate. The method can form a recess extending through the common non-conductive material to the conductive material, the recess defining a corner at least adjacent the interface between the conductive material and the general non-conductive material. The method may further include removing at least a portion of the conductive material from the corners to at least partially blunt the corners by exposing the corners to dislocations.

The invention also relates to a microelectronic substrate formed by a method that may include placing a common nonconductive material adjacent to a conductive material of a microelectronic substrate and forming a recess extending through the common nonconductive material to the conductive material. It is about. The recess defines a corner at least adjacent the interface between the conductive material and the general non-conductive material. The method may further comprise removing at least some conductive material from the corner to at least partially blunt corner.

In another aspect of the invention, the microelectronic substrate can be formed by a method comprising disposing an electrolyte fluid adjacent to a conductive material of the microelectronic substrate, the conductive material being in contact with the first surface of the first plane. And a recess in the first surface. The recess may be surrounded by a second surface of the second plane, and the conductive material may have a corner between the first surface and the second surface. The method includes removing at least a portion of the conductive material from the corner by placing the first electrode and the second electrode in fluid communication with the electrolyte fluid, and by coupling at least one of the electrodes to the front panel, thereby conducting the conductive material from the corner. It may further comprise the step of removing at least a portion of the.

1A-C schematically illustrate a shallow trench isolation process for forming a semiconductor form on a semiconductor substrate in accordance with the prior art;

2A-B are side elevation views, partially and schematically, of an apparatus for removing conductive material from a semiconductor substrate in accordance with the prior art;

3 is a partial and schematic side elevation view of a device having a pair of electrodes and a support member for removing conductive material from a microelectronic substrate, in accordance with an embodiment of the present invention.

FIG. 4 is a partial and schematic side elevation view of a device for removing a conductive material and sensing characteristics of a microelectronic substrate from which the material is removed in accordance with another embodiment of the present invention. FIG.

Figure 5 is a side elevational view, partially and schematically, of a device comprising two electrolytes in accordance with another embodiment of the present invention.

6 is a plan view partially and schematically showing a substrate adjacent a plurality of electrodes in accordance with a further embodiment of the present invention.

7 is a cross-sectional side view of a substrate and an electrode in accordance with another embodiment of the present invention.

8A is a partial and schematic view of the same size of a portion of a support for receiving electrode pairs according to another embodiment of the present invention;

8B-8C show electrodes of the same size in accordance with a further embodiment of the present invention.

9A and 9B schematically illustrate circuits and waveforms for electrolytically treating a microelectronic substrate in accordance with another embodiment of the present invention.

10A-10F schematically illustrate a process for rounding or blunting the edges of gaps in a conductive material of a microelectronic substrate in accordance with one embodiment of the present invention.

FIG. 11 is a partial and schematic illustration of a process for rounding or blunting the corners of a gap of a conductive material of a microelectronic substrate in accordance with another embodiment of the present invention. FIG.

The present disclosure describes a substrate assembly used in the manufacture of a microelectronic device and / or a method and apparatus for removing conductive material from the microelectronic substrate. Many specific embodiments of the present invention are described in the following description and in FIGS. 3 to 11 in order to provide a thorough understanding of the above embodiments. However, those skilled in the art will appreciate that the present invention may be practiced with additional embodiments or without the following detailed description.

3-9B and related descriptions generally relate to an apparatus for removing a conductive material from a microelectronic substrate in accordance with an embodiment of the present invention. 10A-11 and related descriptions relate to a technique for rounding or blunting corners of the conductive material, for example by using a device of the type described with respect to FIGS. 3-9B. As used herein, the term conductive material includes metals such as copper, platinum, and aluminum, as well as semiconductor materials such as doped silicon and / or polysilicon. The term microelectronic substrate is generally referring to substrate assemblies configured to support microelectronic portions, such as semiconductor devices.

FIG. 3 is a partial and schematic side elevation view of a device 160 for removing conductive material from a substrate assembly 110 or a microelectronic substrate in accordance with an embodiment of the present invention. In one form of this embodiment, the device 160 includes a container 130 containing an electrolyte 131 that may be in a liquid or gel state. As used herein, the terms electrolyte and electrolyte fluid generally refer to an electrolyte liquid or gel. Structures in fluid communication with the electrolyte fluid are thus in fluid communication with the electrolyte liquid or gel.

Microelectronic substrate 110 has an edge surface 112 and two face surfaces 113. The support member 140 is attached to the microelectronic substrate 110 with respect to the container 130 such that the conductive layer 111 on at least one of the face surfaces 113 of the substrate 110 contacts the electrolyte 131. Support. The conductive layer 111 may comprise a metal such as platinum, tungsten, tantalum, gold, copper or other conductive material. In another form of this embodiment, the support member 140 is coupled to the substrate drive unit 141 which moves the microelectronic substrate 110 and the support member relative to the container 130. For example, the substrate drive unit 141 translates the support member 140 (as indicated by arrow "A") and / or moves the support member 140 (as indicated by arrow "B"). Can be rotated.

The device 160 may further comprise a first electrode 120a and a second electrode 120b (collectively referred to as electrode 120), which is supported by the support member 124 to form the microelectronic substrate 110. Is supported. In one aspect of this embodiment, the support arm 124 is coupled to the electrode drive unit 123 to move the electrode 120 relative to the microelectronic substrate 110. For example, the electrode drive unit 123 moves the electrode toward and away from the conductive layer 111 of the microelectronic substrate 110 (indicated by arrow “C”) and / or the conductive layer 111. Can be moved in a transverse direction (indicated by an "arrow" D ") in a plane that is substantially parallel to the electrode. Alternatively, the electrode drive unit 123 can move the electrode in a different form or the substrate drive unit 141 ) Provides sufficient relative motion between the substrate 110 and the electrode 120, the electrode drive unit 123 can be removed.

In the embodiment described above with reference to FIG. 3, the electrode 120 is connected to the power source 121 with a conductive wire 128 for supplying current to the electrolyte 131 and the conductive layer 111. In operation, the power source 121 supplies an alternating current (single phase or polyphase) to the electrode 120. The current passes through the electrolyte 131 and reacts electrochemically with the conductive layer 111 to remove material (eg, atoms or groups of atoms) from the conductive layer 111. Electrode 120 and / or substrate 110 may move relative to each other to remove material from selected portions of conductive layer 111 or from the entire conductive layer 111.

In one aspect of the embodiment of the device 160 shown in FIG. 3, the distance D ₁ between the electrode 120 and the conductive layer 111 is the distance between the first electrode 120a and the second electrode 120b. It is set smaller than (D ₂ ). In addition, the electrolyte 131 has a substantially higher resistance than the conductive layer 111. Therefore, the alternating current flows from the first electrode 120a to the conductive layer 111 through the electrolyte 131 rather than directly from the first electrode 120a to the second electrode 120b through the dielectric 131. Again following the lowest resistance path through the electrolyte 131 to the second electrode 120b. Alternatively, a low dielectric material (not shown) is positioned between the first electrode 120a and the second electrode 120b to allow direct electrical communication between the electrode 120 and not the first passage through the conductive layer 111. Can break communication.

One feature of the embodiment of the device 160 shown in FIG. 3 is that the electrode 120 does not contact the conductive layer 111 of the substrate 110. An advantage of this arrangement is that it is possible to remove residual conductive material resulting from the direct electrical connection between the electrode 120 and the conductive layer 111 described above with reference to FIGS. 1 and 2. For example, device 160 may remove residual conductive material adjacent to the contact area between the conductive layer and the electrode because electrode 120 does not contact conductive layer 111.

Another feature of the embodiment of the device 160 described above with reference to FIG. 3 is that the substrate 110 and / or the electrode 120 move relative to each other to move the electrode 120 to a predetermined point adjacent to the conductive layer 111. Can be located. The advantage of this arrangement is that the electrodes 120 can be sequentially positioned adjacent all parts of the conductive layer to remove material from the entire conductive layer 111. Alternatively, when only a selected portion of the conductive layer 111 is desired to be removed, the electrode 120 can be moved to these selected portions and the remaining portion of the conductive layer 111 can be left in a circle.

4 is a partial schematic side view of an apparatus 260 that includes a support member 240 positioned to support a substrate 110 in accordance with another embodiment of the present invention. In an aspect of this embodiment, the support member 240 supports the substrate 110 with the conductive layer 111 raised. The substrate driving unit 241 may move the substrate 110 and the supporting member 240 as described above with reference to FIG. 3. The first and second electrodes 220a and 220b are positioned on the conductive layer 111 and are connected to the power source 221. The support member 224 supports the electrode 220 relative to the substrate 110 and moves the electrode 220 over the surface of the support conductive layer 111 in substantially the same manner as described above with reference to FIG. 3. The electrode driving unit 223 is connected.

In one aspect of the embodiment shown in FIG. 4, the apparatus 260 further includes an electrolyte container 230 having a supply conduit 237 having an opening 238 positioned adjacent to the electrode 220. Accordingly, the electrolyte 231 may be locally disposed in the interface region 239 between the conductive layer 111 and the electrode 220 without covering the entire conductive layer 111. The conductive material removed from the electrolyte 231 and the conductive layer 111 flows over the substrate 110 and is collected in the electrolyte container 232. The mixture of electrolyte 231 and conductive material may flow into a reclaimer 233 that removes most of the conductive material from the electrolyte 231. A filter 234 located downstream of the reclaimer 233 provides additional filtration of the electrolyte 231, and the pump 235 delivers the reconditioned electrolyte 231 through the return conduit 236 to the electrolyte vessel. Return to 230.

In another aspect of the embodiment shown in FIG. 4, the device 260 processes a sensor assembly 250 having a sensor 251 disposed adjacent the conductive layer 111 and a signal generated by the sensor 251. It may include a sensor control unit 252 connected to the sensor 251 to. In addition, the control unit 252 may move the sensor 251 with respect to the substrate 110. In another aspect of this embodiment, the sensor assembly 250 may be connected to the electrode drive unit 223 and / or the substrate drive unit 241 through a feedback path 253. Thus, the sensor 251 can determine which regions of the conductive layer 111 require additional material removal, and move the electrodes 220 and / or substrate 110 relative to each other to move the electrodes 220 to them. It can be located above the area. Alternatively (eg, when the removal process is very repetitive), the electrodes 220 and / or the substrate 110 may move relative to each other according to a predetermined movement plan.

Sensor 251 and sensor control unit 252 may have any suitable number of configurations. For example, in one embodiment, sensor 251 detects removal of conductive layer 111 by detecting changes in intensity, wavelength, or phase shift of light reflected from substrate 110 when the conductive material is removed. It may be an optical sensor. Alternatively, sensor 251 can emit radiation having a different wavelength, such as x-ray radiation and detect its reflection. In another embodiment, the sensor 251 may measure a change in resistance or capacitance of the conductive layer 111 between two selected points. In another aspect of this embodiment, one or both of the electrodes 220 can perform the function of the sensor 251 (along with the material removal function described above), eliminating the need for a separate sensor 251. do. In another embodiment, the sensor 251 may detect a change in voltage and / or current drawn from the power source 221 when the conductive layer 111 is removed.

In certain embodiments described above with reference to FIG. 4, the sensor 251 may be spaced apart from the electrolyte 231 because the electrolyte 231 may be disposed between the electrode 220 and the conductive layer 111. This is because it is concentrated in the interface area 239. Therefore, since the operation of the sensor 251 and the electrolyte 231 less interfere, the accuracy with which the sensor determines the progress of the electrolytic process can be improved. For example, when sensor 251 is an optical sensor, since sensor 251 is disposed away from interface area 239, electrolyte 231 degrades radiation reflected from the surface of substrate 110 less.

Another feature of the embodiment of the device 260 described above with reference to FIG. 4 is that the electrolyte supplied to the interface region 239 is continuously replenished with either a reconditioned electrolyte or a fresh electrolyte. An advantage of this feature is that the electrochemical reaction between the electrode 220 and the conductive layer 111 is high and can be maintained at a constant level.

5 is a partial schematic side view of an apparatus 360 for guiding alternating current to the substrate 110 through a first electrolyte 331a and a second electrolyte 331b. In one aspect of this embodiment, the first electrolyte 331a is disposed in two first electrolyte containers 330a, and the second electrolyte 331b is disposed in second electrolyte container 330b. The first electrolyte container 330a is partially immersed in the second electrolyte 331b. Apparatus 360 may further comprise electrodes 320, shown as first electrode 320a and second electrode 320b, each of which is connected to a power source 321, each of which is a first electrolyte container 330a. ) Is housed in one of. Alternatively, one of the electrodes 320 can be grounded. The electrode 320 may include materials such as silver, platinum, copper and / or other materials, and the first electrolyte 331a may be formed of sodium chloride, potassium chloride, copper sulfate, and / or materials forming the electrode 320. And other electrolytes that may coexist.

In one aspect of this embodiment, the first electrolyte container 330a is a sintered material such as Teflon ^™ , sintered glass, quartz or sapphire, or ions pass back and forth between the first electrolyte container 330a and the second electrolyte container 330b. However, a flow restrictor, such as a permeable separator formed of other suitable porous material, that does not allow the second electrolyte 330b to pass into the electrode 320 (eg, in a manner substantially similar to a salt bridge). 322. Alternatively, the first electrolyte 331a is outwardly through the flow restrictor 322 in such a state that the first electrolyte 331a or the second electrolyte 330b cannot return through the flow restrictor 322. The first electrolyte 331a may be supplied from the first electrolyte source 339 to the electrode container 330a at a pressure and a speed sufficient to guide the first electrolyte 331a. In certain embodiments, the second electrolyte 331b remains electrically connected to the electrode 320 by the flow of the first electrolyte 331a through the restrictor 322.

In one aspect of this embodiment, the device 360 may also include a support member 340 that supports the substrate 110 with the conductive layer 111 facing toward the electrode 320. As an example, the support member 340 is disposed in the second electrolyte container 330b. In another aspect of this embodiment, the support member 340 and / or the electrode 320 can be moved relative to each other by one or more drive units (not shown).

One feature of the embodiment of the device 360 described above with reference to FIG. 5 is that the first electrolyte 331a can be selected to coexist with the electrode 320. An advantage of this feature is that the first electrolyte 331a degrades the electrode 320 less than the conventional electrolyte. Conversely, the second electrolyte 331b may be selected without considering its effect on the electrode 320 because the second electrolyte is chemically separated from the electrode 320 by the flow restrictor 322. Because there is. Therefore, the second electrolyte 331b may include hydrofluoric acid or another auxiliary agent that actively reacts with the conductive layer 111 of the substrate 110.

6 is a top view of a microelectronic substrate 110 positioned below a plurality of electrodes having a configuration and shape in accordance with some embodiments of the present invention. For illustration purposes, several different electrodes are placed in close proximity to the same microelectronic substrate 110, but in practice, the same type of electrodes can be positioned relative to a single microelectronic substrate.

In one embodiment, electrodes 720a and 720b may be grouped to form electrode pair 770a, with each electrode 720a and 720b connected to an opposite terminal of power source 121 (FIG. 3). The electrodes 770a and 770b may have an elongate or strip shape and may be arranged to extend parallel to each other over the diameter of the substrate 110. The space between adjacent electrodes of electrode pair 370a may be selected to direct current to substrate 110 as described above with reference to FIG. 3.

In alternative embodiments, electrodes 720c and 720d may be grouped to form electrode pairs 770b, each of which 720c and 720d being tapered inwardly into the center of microelectronic substrate 110 or " pie " pie) "shape. In yet another embodiment, the narrow strip electrode 720e and 720f has a radius from each electrode 720e and 720f toward the outer periphery 112 of the microelectronic substrate 110 from the center 113 of the microelectronic substrate 110. In a state extending outwardly, they may be grouped to form electrode pairs 770c.

In another embodiment, the single electrode 720g may extend over approximately half of the area of the microelectronic substrate 110 and may have a semi-circular planar shape. The electrodes 720g may be grouped with other electrodes (not shown) having a shape corresponding to the mirror image of the electrodes 720g, both electrodes being in any manner described above with reference to FIGS. It may be connected to the power source 121 to provide an alternating current to the microelectronic substrate.

FIG. 7 is a partial schematic side cross-sectional view of a portion of a substrate 110 positioned below electrode 720c described above with reference to FIG. 6. In one aspect of this embodiment, the electrode 720c has an upper surface 771 and a lower surface 772 facing the conductive surface 111 of the substrate 110 while facing the upper surface 771. In one aspect of this embodiment for providing a wedge-shaped profile for electrode 720c, the bottom surface 772 is tapered downward from the center 113 of the substrate 110 toward the outer periphery 112 of the substrate 110. Can be. Alternatively, electrode 720c may have a planar structure with a lower surface 772 positioned as shown in FIG. 7 and an upper surface 771 parallel to the lower surface 772. A feature of certain embodiments is that electrical coupling between the electrode 720c and the substrate 110 can be stronger towards the outer periphery 112 of the substrate 110 than toward the center 113 of the substrate 110. This feature is such that when the outer periphery 112 of the substrate 110 moves relative to the electrode 720c at a faster speed than the center 113 of the substrate 110, for example, the substrate 110 is moved around its center 113. When rotating, it is advantageous. Therefore, the electrode 720c may be shaped in consideration of the relative motion between the substrate 110 and the electrode.

In other embodiments, electrodes 720c may have other shapes. As an example, the bottom surface 772 can have a curved shape instead of a flat profile. Alternatively, certain electrodes (or other electrodes having shapes other than those shown in FIG. 6) described above with reference to FIG. 6 may have a sloped or curved bottom surface. In still other embodiments, the electrodes may have other shapes that take into account relative motion between the substrate 110 and the electrodes.

8A is a partial schematic diagram of an electrode support 473 for supporting a plurality of electrodes in accordance with another embodiment of the present invention. In one aspect of this embodiment, the electrode support 473 may include a plurality of electrode gaps 474, each of which accommodates either the first electrode 420a or the second electrode 420b. The first electrode 420a is connected to the first lead 428a through the gap 474, and the second electrode 420b is connected to the second lead 428b. Both leads 428a and 428b are connected to a power source 421. Thus, each pair 470 of the first and second electrodes 420a and 420b forms part of a circuit completed by the electrolyte (s) and substrate 110 described above with reference to FIGS.

In one form of this embodiment, the first lead 428a may be offset from the second lead 428b to reduce the possibility of capacitive coupling and / or short circuit between the leads. In a further form of this embodiment, electrode support 473 may generally have a configuration similar to any of those described above with respect to FIGS. For example, any of the individual electrodes (i.e., 320a, 320c, 320e, or 320g) described above with reference to FIG. 6 may each include a plurality of electrodes receiving one of the first electrode 420a or the second electrode 420b. It can be replaced with an electrode support 473 that includes a gap 474 and has the same overall shape.

In a further form of this embodiment, the electrode pairs 470 shown in FIG. 8A may be arranged in a manner corresponding to the vicinity between the electrodes 420a and 420b and the microelectronic substrate 110 (FIG. 7) and The electrode pairs 470 may be arranged to correspond to the speed of relative operation between the electrodes 420a and 420b and the microelectronic substrate 110. For example, the electrode pair 470 is more concentrated at the periphery 112 of the microelectronic substrate 110 or the relative speed between the electrode pair 470 and the microelectronic substrate 110 is relatively high (see FIG. 7). ) Can be concentrated in other areas. Thus, increasing concentrations of electrode pairs 470 can provide increased electrolyte flow to compensate for relatively high velocities. In addition, when the first electrode 420a and the second electrode 420b of each electrode pair 470 are adjacent to the conductive layer 111, a direct electrical bond between the first electrode 420a and the second electrode 420b may occur. As this reduces the likelihood, the electrodes may be relatively adjacent together in an area (such as the periphery 112 of the microelectronic substrate 110) adjacent to the conductive layer 111 (see FIG. 7). In a further form of this embodiment, the amplitude, frequency, and / or waveform supplied to the other electrode pair 470 may include the space between the electrode pair 470 and the microelectronic substrate 110, and the electrode pair 470 and the microelectronic. It may depend on factors such as the relative speed between the substrates 110.

8B and 8C show electrodes 820 (shown as first electrode 820a and second electrode 820b) arranged concentrically in accordance with a further embodiment of the present invention. In one embodiment shown in FIG. 8B, the first electrode 820a may be disposed concentrically around the second electrode 820b, and the dielectric material 829 may be the first electrode 820a and the second electrode 820b. ) May be disposed between. The first electrode 820a may define a full 360 degrees around the second electrode 820b, as shown in FIG. 8B, or alternatively the first electrode 820a may define an arc of 360 degrees or less. can do.

In another embodiment, the first electrode 820A shown in FIG. 8C may be disposed concentrically between the second electrode 820b, with the dielectric material 829 disposed between the neighboring electrodes 820. have. In one form of this embodiment, a current can be supplied to each of the second electrodes 820b without a phase change. Alternatively, the current supplied to one second electrode 820b may be changed in phase with respect to the current supplied to another second electrode 820b. In a further form of this embodiment, the current supplied to each second electrode 820b may differ in non-phase characteristics, eg amplitude.

One form of the electrodes 820 described above with respect to FIGS. 8B and 8C allows the first electrode 820a to block the second electrode (s) 820b from interference from other power sources. For example, the first electrode 820a may be grounded to block the second electrodes 820b. One advantage of this configuration is that the current applied to the microelectronic substrate 110 (FIG. 7) through the electrode 820 can be more accurately controlled.

9A is a schematic circuit diagram of some of the elements described above with respect to FIGS. 3-8C. As shown in FIG. 9A, the power source 521 is coupled to the first electrode 520a and the second electrode 520b as conductive wires 528a and 528b, respectively. Electrodes 520a and 520b are connected to microelectronic substrate 110 with electrolyte 531 in a device schematically represented by two sets of parallel capacitors and resistors. The third capacitor and resistor schematically indicate that the substrate 110 "floats" with respect to ground or other potential.

In one form of the embodiment shown in FIG. 9A, the power source 521 may be coupled to an amplitude adjuster 522 that adjusts the signal produced by the power source 521, as shown in FIG. 9B. Accordingly, the power supply 521 may generate the high frequency 904, and the amplitude adjuster 522 may superimpose the low frequency 902 on the high frequency 904. For example, high frequency 904 may include a series of positive or negative voltage spikes received within a square wave envelope defined by low frequency 902. Each spike of the high frequency 904 may have a relatively steep rise time gradient and a more gradual fall time gradient that transfers charge through the dielectric to the electrolyte. The fall time gradient may define a straight line, as indicated by the high frequency 904a, as indicated by the high frequency 904a. In another embodiment, the high frequency 904 and the low frequency 902 can be, for example, the special characteristics of the electrolyte and dielectric material adjacent to the electrodes 420, the target rate at which the material is removed from the substrate 110 and / or the substrate. It may have other forms depending on the characteristics of 110.

The advantage of this configuration is that the low frequency superimposition signal can more effectively promote the electrochemical reaction between the conductive layer 111 and the electrolyte 531 of the microelectronic substrate 110, with the high frequency signal being the electrodes 520a, 520b. Can transfer necessary electrical energy to the microelectronic substrate 110. Thus, certain embodiments described above with respect to FIGS. 3-8C may include an amplitude regulator in addition to the power source.

10A-F schematically illustrate the process of forming a portion in a microelectronic substrate in accordance with another embodiment of the present invention by using any of the devices described above with respect to FIGS. 3-8C. In one form of this embodiment, the method includes forming a shallow trench isolation (STI) portion, and in another embodiment, forming another type of portions. In any of the above embodiments, the method may include rounding or blunting corners of the conductive material, as described in more detail below.

10A illustrates a portion of a microelectronic substrate 1010 having a face surface 1013 having a conductive material, a partial conductive material and / or a semiconductor material 1011 (collectively described as conductive material 1011). Illustrated. For example, in one embodiment, the conductive material 1011 may comprise silicon doped with boron or phosphorus. In other embodiments, the conductive material 1011 may include other conductive materials or semiconductor materials. In any of the above embodiments, the method may further comprise forming a gap in the conductive material 1011 to support the dielectric material or other microelectronic morphology. In one form of embodiment, the method may include disposing an oxide layer 1014 on a conductive material 1011 and disposing a nitride layer 1015 on the oxide layer 1014. A mask 1016 having an opening 1017 corresponding to the desired location in the form of microelectronics is disposed adjacent to the nitride layer 1015 and the microelectronic substrate 1010 is exposed to an etchant.

As shown in FIG. 10B, the etchant may form gaps 1060 or other recesses extending through the nitride layer 1015, the oxide layer 1014, and the upper layer 1065 of the conductive material 1011. The material disposed under the openings 1017 may be removed. Thus, the gaps 1060 may generally include sidewalls 1064 across the top layer 1065 and corners 1063 of the junction between the sidewalls 1064 and the top layer 1065.

In FIG. 10C, nitride layer 1015 and oxide layer 1014 may be etched at corner 1063 before corners 1063 are rounded or blunt formed. For example, in one form of this embodiment, about 500 parts for about one part hydrofluoric acid and about one part hydrochloric acid to expose the top layer 1065 of the conductive material 1011 near the corner 1063. A liquid etchant having a portion of water may etch back the nitride layer 1015 and the oxide layer 1014 at approximately the same rate. In another form of this embodiment, the etching process may be completed at a temperature of about 60 ° C. In another embodiment, etching the nitride layer 1015 and the oxide layer 1014 from the corner 1063 may be removed, as described in more detail below with respect to FIG. 11.

As shown in FIG. 10D, the exposed corners 1063 may be rounded or blunted to form rounded corners 1063a (shown in dashed lines in FIG. 10D). For example, in one embodiment of this embodiment, the electrolyte fluid 1031 may be disposed adjacent to the corner 1063, and the first electrode 1020a and the second electrode 1020b (collectively the electrode 1020). It can be arranged in fluid communication with. In another form of this embodiment, the electrodes 1020 may be spaced apart from the microelectronic substrate 1010 by an interval of about 1 to 2 millimeters. In other embodiments, the interval may have a different value. At least one electrode 1020 may be connected to an electrical power source, such as an alternating current power source, in a manner generally similar to that described above with respect to FIGS. 3-9B. Thus, current tends to flow through the electrolyte fluid 1031 at one of the electrodes 1020 to the corner 1063 to oxidize the conductive material at the corner 1063. Current moves through the conductive material 1011 and back through the electrolyte fluid 1031 to the other electrode 1020 to complete the electrical circuit. The oxidized material of the corner 1063 can be removed by chemically interacting with the electrolyte fluid to form the rounded corner 1063a.

In one form of this embodiment, the current flows from the electrolyte fluid 1031 at a rate of about one to about 500 mA / cm ² (in a particular embodiment, about 50 mA / cm ² ) and a frequency of about 60 Hz and a voltage of about 15 V _rms . Is introduced. Alternatively, the current may have other characteristics. In any of the above embodiments, the composition of the electrolyte fluid 1031 may be the same as the composition of the etchant used to etch back the oxide layer 1014 and the nitride layer 1015. In another form of this embodiment, the configuration of the electrolyte fluid 1031 may be selected to reduce or eliminate etching at the sidewalls 1064 of the gap 1060. For example, when the conductive material 1011 comprises silicon, hydrochloric acid of the electrolyte fluid 1031 may reduce the pH of the fluid, thereby reducing at least etching of the sidewall 1064. Thus, the electrolyte fluid 1031 is sufficiently conductive to conduct a current to the corner 1063 to oxidize the conductive material at the corner 1063 (a) and is sufficient to remove the oxidized material at the corner 1063. (B) is not reactive enough to remove non-oxidized material from sidewall 1064 of gap 1060. Alternatively, ethane glycol may be added to the electrolyte fluid 1031 to reduce the etch rate of the silicon sidewall 1064. In another embodiment, as described above, it may be disposed in the electrolyte fluid 1031 to control the material removal rate at the sidewall 1064 while allowing material to be removed from the corners 1063.

FIG. 10E shows a portion of the microelectronic substrate 1010 shown in FIG. 10D after the corner 1063 (FIG. 10D) is rounded to form a blunt corner 1063a. In one form of this embodiment, the cross section of the corner 1063a may define an almost circular arc. In other embodiments, the blunt corners 1063a may have other shapes. In some embodiments of the above, the blunt corner 1063a may be rounded or less sharp than the sharp corner 1063 shown in FIG. 10D.

10F shows the gate oxide material 1066 disposed in the gap 1060 to coat the sidewall 1064. Gates may be formed by placing conventional gate material 1067 in gate oxide 1066 within gap 1060.

One form of embodiment of the process described above with respect to FIGS. 10A-F is that the initial sharp corner 1063 formed at the junction between the top layer 1065 and the sidewall 1064 of the conductive material 1011 is the temperature of the microelectronic substrate 1110. Can be dulled or rounded without significantly rising above room temperature. Thus, the bluntly formed corners 1063a emit less electromagnetic signals during operation of the microelectronic substrate 1010, which interferes with other forms of the microelectronic substrate 1010. In addition, the microelectronic substrate can be made cheaper and more reliable as a result of less time spent in high temperature environments.

Another form of embodiment of the method described above with respect to FIGS. 10A-F is that the method is self-defined. For example, since the conductive material 1011 of the corner 1063 is oxidized and etched, the corner 1063 is more blunt and less likely to draw current faster than other conductive surfaces in fluid communication with the electrode 1020. Lose. Thus, the method need not be monitored in close proximity to other material removal processes.

FIG. 11 shows, in part and in schematic form, a process for rounding or blunting the conductive corners of the microelectronic substrate 1110 according to another embodiment of the present invention. In one form of this embodiment, the microelectronic substrate 1110 may include a nitride layer 1115, an oxide layer 1114 and a conductive material 1111 which are generally arranged in the same manner as described above with respect to FIG. 10B. . The gaps 1160 are generally etched into the conductive material 1111 through the nitride layer 1115 and the oxide layer 1114 in a manner similar to that described above with respect to FIG. 10B. The gaps 1160 may have sidewalls 1164 that form sharp corners 1163 at which the gaps 1160 intersect the top surface 1165 of the conductive materials 1111.

In a further form of this embodiment, the first electrode 1120a and the second electrode 1120b initially have sharp corners 1163 without first etching back the oxide layer 1114 and the nitride layer 1115 at the corner 1163. ) May be placed in fluid communication with the electrolyte 1131 disposed on the microelectronic substrate 1110. Thus, oxide layer 1114 and nitride layers 1115 initially extend over rounded corners 1063a until at least oxide layer 1114 and nitride layers 1115 are removed from microelectronic substrate 1110. There may be. An advantage of the method is that the steps described above with respect to FIG. 10C can be eliminated.

In the foregoing description, although specific embodiments of the invention have been described herein for illustrative purposes, it will be understood that various modifications may be made within the spirit and scope of the invention. For example, the processes described above can be used to form other portions in addition to the STI portions. Accordingly, the invention is limited only by the appended claims.

Claims (71)

In a method of processing a microelectronic substrate: Disposing an electrolyte fluid adjacent the conductive material of the microelectronic substrate, the conductive material having a first surface of a first plane and a recess of the first surface, the recess having a second The electrolyte fluid placement step bound by a second surface of the plane, the conductive material further comprising a corner between the first surface and the second surface; Removing at least a portion of the conductive material from the corner by arranging the electrolyte fluid and the first and second electrodes in fluid communication and coupling at least one of the electrodes to a source of electric potential. A microelectronic substrate processing method comprising a. The method of claim 1, The microelectronic substrate has a first face surface, the recess generally extends across the face surface, and removing at least a portion of the conductive material comprises placing the two electrodes facing the face surface. Making a step; Coupling at least one of the electrodes to the front panel; Disposing an electrolyte fluid between the face surface and the electrodes. The method of claim 1, Radiating electrical signals from an electrode spaced from the microelectronic substrate; Receiving the electrical signals at a corner of the conductive material; Oxidizing at least a portion of the conductive material of the corner by passing the electrical signals through the conductive material; Exposing the oxidized portion of the conductive material to a chemical etchant. The method of claim 1, The first surface of the conductive material is disposed adjacent to a general nonconductor material, the general nonconductor material is disposed between the first surface and at least one of the electrodes, and from the corner of the conductive material Removing at least a portion; removing the conductive material in combination with the general non-conductive material. The method of claim 1, Disposing a general insulator layer on the conductive material; Removing at least a portion of the insulator layer to expose a corner of the conductive material prior to removing at least a portion of the conductive material from the corner. The method of claim 1, Disposing an oxide layer on the conductive material; Disposing a nitride layer on the oxide layer; Removing at least a portion of the nitride layer and at least a portion of the oxide layer to expose a corner of the conductive material prior to removing the conductive material from the corner. The method of claim 1, Removing the conductive material comprises oxidizing at least a portion of the conductive material by passing a current through at least a portion of the conductive material; Exposing the oxidized portion to an etchant. The method of claim 1, Selecting the electrolyte to include at least one of hydrochloric acid and hydrofluoric acid and water. The method of claim 1, Removing at least a portion of the conductive material comprises passing a current through the conductive material at a rate of about 1 to 500 milliamps per square centimeter. The method of claim 1, Removing at least a portion of the conductive material includes selecting a substrate to provide about 15 volts _rms to the conductive material. The method of claim 1, Removing at least a portion of the conductive material includes selecting a current through the conductive material to vary at about 60 Hz. The method of claim 1, Removing at least a portion of the conductive material comprises selecting a current through the conductive material to be alternating current. The method of claim 1, Selecting the electrolyte fluid to include water, hydrochloric acid and hydrofluoric acid in a ratio of about 500: 1: 1. The method of claim 1, Selecting the conductive material to include doped silicon. The method of claim 1, And selecting at least one of the first electrode and the second electrode to include at least one of platinum, tantalum, and graphite. The method of claim 1, And disposing at least one of the first electrode and the second electrode at a distance of about 1 to 2 millimeters from the microelectronic substrate. The method of claim 1, After removing material from the corner, further comprising disposing an insulating layer on the walls of the recess. The method of claim 1, And disposing a dielectric material in the recess. The method of claim 1, At least a portion of the conductive material comprises reducing the rate at which the conductive material is removed from the corner by rounding the corner. In a method of processing a microelectronic substrate: Disposing a common nonconducting material adjacent the conductive material of the microelectronic substrate; Forming a recess extending through the common non-conductive material to the conductive material, the recess defining a corner at least adjacent an interface between the conductive material and the general non-conductive material; Removing at least a portion of the conductive material from the corners to at least partially blunt the corners by exposing the corners to dislocations. The method of claim 20, Removing at least a portion of the conductive material may include placing the first electrode and the second electrode adjacent to the microelectronic substrate and spaced apart from the microelectronic substrate; Coupling at least one of the electrodes to the front panel; Passing a current from at least one of the electrodes to the corner to oxidize the conductive material at the corner; Exposing the oxidized conductive material of the corner to an etchant. The method of claim 20, Radiating electrical signals from an electrode spaced from the microelectronic substrate; Receiving the electrical signals at a corner of the conductive material; Oxidizing at least a portion of the conductive material of the corner by passing the electrical signals through the conductive material; Exposing the oxidized portion of the conductive material to a chemical etchant. The method of claim 20, Removing at least a portion of the conductive material from the corners includes removing the conductive material in combination with the general non-conductive material. The method of claim 20, Removing at least a portion of the nonconductive material to expose a corner of the conductive material prior to removing at least a portion of the conductive material from the corner. The method of claim 20, Disposing an oxide layer on the conductive material; Disposing a nitride layer on the oxide layer; Removing at least a portion of the nitride layer and at least a portion of the oxide layer to expose a corner of the conductive material prior to removing at least a portion of the conductive material from the corner. . The method of claim 20, Removing the conductive material comprises oxidizing at least a portion of the conductive material by passing a current through at least a portion of the conductive material; Exposing the oxidized portion to an etchant. The method of claim 20, Removing at least a portion of the conductive material comprises passing a current through the conductive material at a rate of about 100 milliamps. The method of claim 20, Removing at least a portion of the conductive material comprises passing a current through the conductive material at a potential of about 15 volts _rms . The method of claim 20, Removing at least a portion of the conductive material comprises passing a current through the conductive material at a frequency of about 60 Hz. The method of claim 20, Removing at least a portion of the conductive material comprises selecting a current through the conductive material to be alternating current. The method of claim 20, Selecting the conductive material to include doped silicon. The method of claim 20, Removing at least a portion of the conductive material may include placing the first electrode and the second electrode in fluid communication with the corner; Coupling at least one of the electrodes to the front panel; Selecting at least one of the first electrode and the second electrode to include at least one of platinum, tantalum and graphite. The method of claim 20, And disposing an insulating layer on the walls of the aperture after removing the material from the corner. The method of claim 20, Forming a transistor gate in the recess. The method of claim 20, The microelectronic substrate has a first face surface, the recess generally extends across the face surface, and removing at least a portion of the conductive material comprises placing the two electrodes facing the face surface. Making a step; Coupling at least one of the electrodes to the front panel; Disposing an electrolyte fluid between the face surface and the electrodes. The method of claim 20, Reducing the rate at which material is removed from the corner by rounding the corner. In a method of processing a microelectronic substrate: Forming an oxide layer on the doped silicon material of the microelectronic substrate; Disposing a nitride layer on the oxide layer; Etching a recess with a conductive material through the nitride layer and the oxide layer; Removing a portion of the nitride layer and oxide layer adjacent the recess to expose a corner of the conductive material; Disposing an electrolyte fluid adjacent a corner of the conductive material; The corner by placing a first electrode and a second electrode adjacent the microelectronic substrate and spaced apart from the microelectronic substrate and in fluid communication with the electrolyte fluid, and coupling at least one of the electrodes to the front panel; Oxidizing at least a portion of the conductive material of; Removing at least a portion of the oxidized material by exposing the oxidized material to an etchant; Reducing the rate at which material is removed from the corner by rounding the corner to reduce the flow of current from the at least one electrode to the corner. The method of claim 37, Removing a portion of the nitride layer and oxide layer adjacent to the recess may include removing material at the first rate from the nitride layer; Removing material from the oxide layer at a second rate, wherein the first rate is about the same as the second rate. The method of claim 37, After removing at least a portion of the oxidized material, further comprising removing the oxide layer and the nitride layer with an etchant. The method of claim 37, Removing a portion of the nitride layer and oxide layer adjacent to the recess includes disposing an etchant adjacent the nitride layer and the oxide layer, the etchant having a chemical composition that is approximately equal to the chemical composition of the electrolyte fluid. A microelectronic substrate processing method having a composition. In a method of processing a microelectronic substrate: Forming a recess in the conductive material of the microelectronic substrate, the recess defining a corner at an intersection of the gap and the plane of the conductive material; Forming a conductive microelectronic feature in the recess; Controlling the electromagnetic radiation from the conductive microelectronic portion by rounding a corner defined by the recess, wherein rounding the corner comprises electrically coupling a front panel to the corner to oxidize the conductive material. Wow; Removing the oxidized material from the corner by exposing the oxidized material to an etchant. 42. The method of claim 41 wherein And forming a recess in the conductive material comprises forming a recess in the semiconductor material. 42. The method of claim 41 wherein Rounding the corners comprises: placing the first electrode and the second electrode adjacent to the microelectronic substrate and spaced apart from the microelectronic substrate; Coupling at least one of the first and second electrodes to a front panel; Passing a current from at least one of the first electrode and the second electrode to the corner through the electrolyte fluid to oxidize the conductive material at the corner; Exposing the oxidized conductive material of the corner to an etchant. 42. The method of claim 41 wherein Radiating electrical signals from an electrode spaced from the microelectronic substrate; Receiving the electrical signals at a corner of the conductive material; Oxidizing at least a portion of the conductive material of the corner by passing the electrical signals through the conductive material; Exposing the oxidized portion of the conductive material to a chemical etchant. 42. The method of claim 41 wherein The conductive material is disposed adjacent to the common non-conductive material, the common non-conducting material is disposed between the plane of the conductive material and the at least one electrode, and removing at least a portion of the conductive material from the corners may comprise: And removing the conductive material associated with the microelectronic substrate. 42. The method of claim 41 wherein Disposing an insulator layer on the conductive material; Removing at least a portion of the non-conductive layer to expose a corner of the conductive material prior to removing at least a portion of the conductive material from the corner. 42. The method of claim 41 wherein Disposing an oxide layer on the conductive material; Disposing a nitride layer on the oxide layer; Removing at least a portion of the nitride layer and at least a portion of the oxide layer to expose a corner of the conductive material prior to removing at least a portion of the conductive material from the corner. . 42. The method of claim 41 wherein Selecting the conductive material to include doped silicon. 42. The method of claim 41 wherein After the corner is rounded, further comprising disposing an insulating layer on the walls of the recess. 42. The method of claim 41 wherein Forming a transistor gate in the recess. 42. The method of claim 41 wherein The microelectronic substrate has a face surface, the recess generally extends across the face surface, and rounding the corner comprises: placing two electrodes facing the face surface; Coupling at least one of the electrodes to the front panel; Disposing an electrolyte fluid between the face surface and the electrodes. Disposing a common nonconducting material adjacent the conductive material of the microelectronic substrate; Forming a recess extending through the common non-conductive material to the conductive material, the recess defining a corner at least adjacent an interface between the conductive material and the general non-conductive material; Removing at least a portion of the conductive material from the corners to at least partially blunt the corners by exposing the corners to dislocations. The method of claim 52, wherein Removing at least a portion of the conductive material may include placing the first electrode and the second electrode adjacent to the microelectronic substrate and spaced apart from the microelectronic substrate; Coupling at least one of the electrodes to the front panel; Passing a current from at least one of the electrodes to the corner to oxidize the conductive material at the corner; Exposing the oxidized conductive material of the corner to an etchant. The method of claim 52, wherein The process, Radiating electrical signals from an electrode spaced from the microelectronic substrate; Receiving the electrical signals at a corner of the conductive material; Oxidizing at least a portion of the conductive material of the corner by passing the electrical signals through the conductive material; Exposing the oxidized portion of the conductive material to a chemical etchant. The method of claim 52, wherein Removing at least a portion of the conductive material from the corners includes removing the conductive material in combination with the general non-conductive material. The method of claim 52, wherein The process further includes removing at least a portion of the nonconducting material to expose the corner of the conductive material before removing at least a portion of the conductive material from the corner. The method of claim 52, wherein The process, Disposing an oxide layer on the conductive material; Disposing a nitride layer on the oxide layer; Removing at least a portion of the nitride layer and at least a portion of the oxide layer to expose a corner of the conductive material prior to removing at least a portion of the conductive material from the corner. The method of claim 52, wherein Removing the conductive material comprises oxidizing at least a portion of the conductive material by passing a current through at least a portion of the conductive material; Exposing the oxidized portion to an etchant. The method of claim 52, wherein The process further includes selecting the conductive material to include doped silicon. The method of claim 52, wherein Removing at least a portion of the conductive material includes selecting a current through the conductive material to be an alternating current. The method of claim 52, wherein The process further comprises disposing an insulating layer on the walls of the recess after removing material from the corner. The method of claim 52, wherein The process further includes forming a transistor gate in the recess. 53. The method of claim 52, wherein removing at least a portion of the conductive material comprises: placing the two electrodes facing the face surface of the microelectronic substrate; Coupling at least one of the electrodes to the front panel; Further comprising disposing an electrolyte fluid between the face surface and the electrodes. Disposing an electrolyte fluid adjacent a conductive material of the microelectronic substrate, the conductive material having a first surface of the first plane and a recess of the first surface, the recess being the second of the second plane; The electrolyte fluid placement step, bounded by a surface, wherein the conductive material further comprises a corner between the first surface and the second surface; Removing at least a portion of the conductive material from the corner by arranging the electrolyte fluid and the first electrode and the second electrode in fluid communication and coupling at least one of the electrodes to a front panel. Formed microelectronic substrate. The method of claim 64, wherein The recess generally extends across the face surface of the microelectronic substrate, and removing at least a portion of the conductive material comprises: placing the two electrodes facing the face surface; Coupling at least one of the electrodes to the front panel; Further comprising disposing an electrolyte fluid between the face surface and the electrodes. The method of claim 64, wherein The process, Radiating electrical signals from at least one of the electrodes, the electrode being spaced apart from the microelectronic substrate; Receiving the electrical signals at a corner of the conductive material; Oxidizing at least a portion of the conductive material of the corner by passing the electrical signals through the conductive material; Exposing the oxidized portion of the conductive material to a chemical etchant. The method of claim 64, wherein The first surface of the conductive material is disposed adjacent to the common non-conductive material, the general non-conducting material is disposed between the first surface and at least one of the electrodes, and removes at least a portion of the conductive material from the corner. Removing the conductive material in combination with the common non-conductive material. The method of claim 64, wherein The process, Disposing an oxide layer on the conductive material; Disposing a nitride layer on the oxide layer; Removing at least a portion of the nitride layer and at least a portion of the oxide layer to expose corners of the conductive material. The method of claim 64, wherein Removing the conductive material comprises oxidizing at least a portion of the conductive material by passing a current through at least a portion of the conductive material; Exposing the oxidized portion to an etchant. The method of claim 64, wherein Removing at least a portion of the conductive material includes selecting a current through the conductive material to be an alternating current. The method of claim 64, wherein The process further includes forming a transistor gate in the gap.

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