KR20000044823A - Manufacturing method for two layered thin film micromirror array-actuated device - Google Patents

Abstract

PURPOSE: A manufacturing method for two layered TMA device is provided to simplify the manufacturing process and to increase the absorption and the adherence of the surface by depositing the sylation agent. CONSTITUTION: A device comprises a driving substrate(210), an insulation layer(211), a metal layer(214), a MOS transistor(212), a blocking layer(216), an upper part protection layer(217), an etching preventing layer(218), an actuator(230), a membrane(231), a lower electrode(232), and an electroplasive(233). A manufacturing method comprises the steps of preparing a driving substrate in which the insulation layer, MOS transistor and the drain electrode are formed; forming the first sacrificial layer in which the supporting part is formed; forming the actuator in which the membrane, lower electrode, and the upper electrode are formed; forming the multi layered second sacrificial layer in which the sylation layer is formed in turn; forming the mirror supporting part by eliminating a part of the second sacrificial layer; forming the mirror layer; and eliminating the first and second sacrificial layer.

Description

Manufacturing method of 2-layer thin film type optical path control device

According to the present invention, a plurality of second sacrificial layers are coated with a planarization material to form an upper surface having a flatness of 95% or more, thereby providing an optimal flatness to the mirror layer formed thereon, thereby increasing the overall light efficiency. The present invention relates to a method for manufacturing a thin film optical path control device having a two-layer structure.

In general, a spatial light modulator, which is an apparatus for projecting optical energy onto a screen, may be variously applied to optical communication, image processing, and information display apparatus. Such devices are classified into a direct view type image display device and a projection type image display device according to a method of projecting a light beam incident from a light source onto a screen. CRT (Cathod Ray Tube) is a direct view type image display device, and a liquid crystal display device (hereinafter referred to as 'LCD'), a deformable mirror device (DMD), or TMA (Thin) is a projection type image display device. film Micromirror Array-actuated).

The above-described CRT apparatus is an excellent display apparatus which is guaranteed an average brightness of 100 ft-L (white display) or more, a contrast ratio of 30: 1 or more, a lifetime of 10,000 hours or more. However, since the CRT has a large weight and volume and maintains high mechanical strength, it is difficult to make the screen completely flat, which causes distortion of the peripheral part. In addition, since CRTs excite phosphors with an electron beam to emit light, there is a problem that a high voltage is required to produce an image.

Therefore, LCDs have been developed to solve the above-mentioned problems of CRT. The advantages of such LCDs are explained in comparison with CRTs. LCDs operate at low voltages, consume less power, and provide images without distortion.

However, despite the advantages described above, the LCD has a low light efficiency of 1 to 2% due to the polarization of the light beam, and there is a problem that the response speed of the liquid crystal material therein is slow.

Accordingly, devices such as DMD or TMA have been developed to solve the problems of the LCD as described above. At present, the TMA can achieve a light efficiency of 10% or more, while the DMD has a light efficiency of about 5%. In addition, the TMA is not only affected by the polarity of the incident light beam, but also does not affect the polarity of the light beam.

Typically, each of the actuators formed inside the TMA causes deformation depending on the electric field generated by the applied image signal and bias voltage. When this actuator causes deformation, each mirror mounted on top of the actuator is inclined in proportion to the magnitude of the electric field.

Thus, these inclined mirrors can reflect light incident from the light source at a predetermined angle. Piezoelectric ceramics such as PZT (Pb (Zr, Ti) O ₃ ) or PLZT ((Pb, La) (Zr, Ti) O ₃ ) are used as a constituent material of the actuator for driving the respective mirrors. As the constituent material of the actuator, electrodistorted ceramics such as PMN (Pb (Mg, Nb) O ₃ ) may be used.

1A to 1G are cross-sectional views illustrating a method of manufacturing a two-layer thin film optical path control apparatus 100 in accordance with the present invention. As shown in FIG. 1A, the two-layer thin film optical path control apparatus is illustrated. The insulating substrate 111, the MOS transistor 112, the diffusion barrier layer 113, the metal layer 114, the lower protective layer 115, the blocking layer 116, and the upper protective layer 117 may be manufactured. It begins with preparation of the drive board 110 in which the prevention layer 118 etc. are formed.

In the driving substrate 110, the MOS transistor 112 includes a gate oxide layer 112a, a gate electrode 112b, an interlayer insulating layer 112c, a source region 112d, a drain region 112e, and a field oxide layer 112f. ) Is formed. The diffusion barrier layer 113 prevents the silicon of the insulating substrate 111 from diffusing into the metal layer 114. The metal layer 114 includes a drain pad 114a and a source region 112d formed to transmit an electrical signal applied from the drain region 112e of the transistor 112 to each actuator 130 to be formed later. ) Is formed of a portion 114b for electrically connecting the plurality of electrodes. The lower protective layer 115 is formed to prevent the blocking layer 116 and the metal layer 114 from being electrically connected to each other. The blocking layer 116 is formed to prevent the photocurrent generated by the photoelectric effect on the metal layer 114 formed below. The upper protective layer 117 is formed to protect the blocking layer 116 and the MOS transistor 112 from being damaged during subsequent manufacturing processes. The etch stop layer 118 is formed to prevent the driving substrate 110 from being damaged during the subsequent etching process.

Subsequently, as shown in FIG. 1B, a first sacrificial layer 120 made of poly-silicon (poly-Si) is formed on the driving substrate 110 by using low pressure vapor deposition (LPCVD). Here, in order to increase the flatness on the upper surface of the first sacrificial layer 120, it is planarized by using spin on glass (SOG) or chemical mechanical polishing (CMP). Subsequently, an upper portion of the drain pad 114a of the first sacrificial layer 120 is formed to etch a portion to form the actuator 130 supporting portion 125.

Subsequently, as shown in FIG. 1C, a membrane 131, platinum (Pt) or platinum / tantalum (Pt / Ta) made of nitride on top of the first sacrificial layer 120 including the actuator support portion 125 is shown. A lower electrode 132 made of a material having excellent electrical conductivity, such as a deformable layer 133 made of a piezoelectric material such as PZT or PLZT, an upper electrode 134 made of the same material as the lower electrode 132, and a lower electrode 132. And an actuator 130 having an electric pipe 135 and the like electrically connected to the drain pad 114a.

Here, looking at the manufacturing process of the actuator 130, first, the membrane 131 made of nitride is formed to a thickness of 0.1-1.0㎛ using a low pressure chemical vapor deposition (LPCVD) method.

Next, a lower electrode 132 made of a metal having excellent electrical conductivity is formed on the membrane 131 to have a thickness of 0.1 to 1.0 μm using a sputtering method.

Next, a strained layer 133 made of a piezoelectric material such as PZT or PLZT is formed on the lower electrode 132 to have a thickness of 0.1 to 1.0 μm using a sputtering or chemical vapor deposition (CVD) method. Subsequently, the strained layer 133 is phase shifted using a rapid heat treatment (RAT) method.

Subsequently, an upper electrode 134 made of a material having the same excellent electrical conductivity as that of the lower electrode 132 is formed on the strained layer 133 by using a sputtering method.

Thereafter, the upper electrodes 134, the deformable layer 133, the lower electrodes 132, and the membrane 131 are divided into respective actuators 130 in a cell unit, and each layer is formed into a desired shape by using a photoresist. Pattern.

Then, the upper electrode 134, the strained layer 133, the lower electrode 132, the membrane 131, the etch stop layer 118, the upper protective layer 117, and the lower protective part from the portion where the drain pad 114a is formed. After the layer 115 is sequentially etched to form a via hole (not shown), a metal such as tungsten (W), platinum (Pt), aluminum (Al), or titanium (Ti) is formed in the via hole. A front tube 135 is formed to connect the lower electrode 132 and the drain pad 114a by using a sputtering method. The lower tube 132 is electrically connected to the lower electrode 132 of the actuator 130 through the drain pad 114a to the MOS transistor 120 of the driving substrate 110. To work.

Subsequently, as shown in FIG. 1D, the flat coating material Accuflo, which is a planarizing material, is formed on the actuator 130 and the exposed first sacrificial layer 120 to a thickness of about 2 μm to 3 μm. As a result, a lower layer 141 having a flatness of about 70% is formed. Here, Accucu is one of the flattening materials produced by AlliedSignal Advanced Microelectronic Material, which has excellent flow characteristics in order to have high flatness and does not contain silicon, but basically forms a combination of carbon (C) and hydrogen (H). It is a substance. Subsequently, a second sacrificial layer 140 having a multilayer structure is formed by forming the upper layer 142 by coating the same material, that is, accucu, on the lower layer 141 to a thickness of about 1 μm to 2 μm.

Next, as shown in FIG. 1E, the second sacrificial layer 140 is partially etched to expose the actuator 130 using photolithography to form the mirror support part 145. do.

Subsequently, as illustrated in FIG. 1F, a material having excellent reflection characteristics such as Al is deposited on the second sacrificial layer 140 and the mirror support portion 145 by using a sputtering method, and then each actuator 130. ) To form one-to-one correspondence to form the mirror layer 150.

Finally, as shown in FIG. 1G, the second sacrificial layer 140 and the first sacrificial layer 120 are removed to complete the TMA device.

However, in the conventional two-layer thin film type optical path control apparatus, when the second sacrificial layer is formed by using a plurality of coatings of the flattening material AccuLop, the upper surface of AccuLop has very low adsorption force, and thus the upper surface of AccuLop is placed on the upper part of AccuLop. When forming the layer, there is a problem that the process is very complicated because it must be deposited or coated for a long time.

The present invention has been made to solve the conventional problems as described above, the object of the present invention as described above, when forming the second sacrificial layer, a silencing agent (Sylation Agent) on the upper surface of the acuflo It is a method of manufacturing a two-layer thin-film optical path control device that can improve the adsorption force of the upper Aculoflo to facilitate the subsequent manufacturing process. time,

The present invention provides a driving substrate including an insulating substrate, a MOS transistor, a diffusion barrier layer, a metal layer, a lower protective layer, a blocking layer, an upper protective layer, an etch stop layer and the like to achieve the above object; Forming a first sacrificial layer having an actuator support portion formed on the driving substrate; Forming an actuator having a membrane, a lower electrode, a deformation layer, an upper electrode, an electric tube, and the like formed on the first sacrificial layer and the actuator support part; Forming a second sacrificial layer of a multilayer in which an acuflo, which is a planarization material, and a sillation agen, which is an adhesive material, are alternately formed on the actuator and the exposed first sacrificial layer; Partially removing the second sacrificial layer to form an mirror support by exposing an actuator; Forming a mirror layer on the second sacrificial layer and the mirror support portion; A method of manufacturing a thin film type optical path control apparatus having a two-layer structure including removing the second sacrificial layer and the first sacrificial layer.

The above objects and various advantages of the present invention will become more apparent from the preferred embodiments of the invention described below with reference to the accompanying drawings by those skilled in the art.

1A to 1G are cross-sectional views illustrating a method for manufacturing a conventional thin film optical path control apparatus having a two-layer structure;

2A to 2G are cross-sectional views illustrating a method for manufacturing a thin film optical path control apparatus having a two-layer structure according to the present invention.

<Description of the symbols for the main parts of the drawings>

210: driving substrate 211: insulating substrate 212: MOS transistor

213: diffusion barrier layer 214: metal layer 215: lower protective layer

216: blocking layer 217: upper protective layer 218: etching prevention layer

220: first sacrificial layer 225: actuator support portion

230: actuator 231: membrane 232: lower electrode

233: strained layer 234: upper electrode 235: electric tube

240: second sacrificial layer 241: lower layer 242: interlayer adhesive layer

243: upper layer 245: mirror support portion 250: mirror layer

Hereinafter, with reference to the accompanying drawings will be described in detail a thin film type optical path control apparatus according to the present invention.

2A to 2G are cross-sectional views illustrating a method of manufacturing a two-layer thin film optical path control apparatus 200 in accordance with the present invention. As shown in FIG. 2A, the two-layer thin film optical path control apparatus is illustrated. The insulating substrate 211, the MOS transistor 212, the diffusion barrier layer 213, the metal layer 214, the lower passivation layer 215, the blocking layer 216, the upper passivation layer 217, and the etching may be manufactured. It begins with preparation of the drive substrate 210 in which the prevention layer 218 etc. are formed.

In the driving substrate 210, the MOS transistor 212 includes a gate oxide layer 212a, a gate electrode 212b, an interlayer insulating layer 212c, a source region 212d, a drain region 212e, and a field oxide layer 212f. ) Is formed. The diffusion barrier layer 213 prevents the silicon of the insulating substrate 211 from diffusing into the metal layer 214. The metal layer 214 is a drain pad 214a and a source region 212d which are formed to transfer an electrical signal applied from the drain region 212e of the transistor 212 to each actuator 230 to be formed later. ) Is formed into a portion 214b that electrically connects them. The lower protective layer 215 is formed to prevent the blocking layer 216 and the metal layer 214 from being electrically connected to each other. The blocking layer 216 is formed to prevent photocurrent caused by a photoelectric effect on the metal layer 214 formed under the blocking layer 216. The upper protective layer 217 is formed to protect the blocking layer 216 and the MOS transistor 212 from being damaged during subsequent manufacturing processes. The etch stop layer 218 is formed to prevent the driving substrate 210 from being damaged during the subsequent etching process.

Subsequently, as illustrated in FIG. 2B, a first sacrificial layer 220 made of poly-silicon (poly-Si) is formed on the driving substrate 210 using low pressure vapor deposition (LPCVD). Here, in order to increase the flatness on the upper surface of the first sacrificial layer 220, it is planarized by using spin on glass (SOG) or chemical mechanical polishing (CMP). Subsequently, an upper portion of the drain pad 214a of the first sacrificial layer 220 may be etched to form an actuator 230 supporting portion 225.

Subsequently, as shown in FIG. 2C, a membrane 231, platinum (Pt) or platinum / tantalum (Pt / Ta) made of nitride on top of the first sacrificial layer 220 including the actuator support portion 125. A lower electrode 232 made of a material having excellent electrical conductivity, such as a deformation layer 233 made of a piezoelectric material such as PZT or PLZT, an upper electrode 234 made of the same material as the lower electrode 232, and a lower electrode 232. And an actuator 230 in which an electric pipe 235 or the like for electrically connecting the drain pad 214a is formed.

Here, looking at the manufacturing process of the actuator 230, first, the membrane 231 made of nitride is formed to a thickness of 0.1-1.0㎛ using a low pressure chemical vapor deposition (LPCVD) method.

Next, a lower electrode 232 made of a metal having excellent electrical conductivity is formed on the membrane 231 to a thickness of 0.1 to 1.0 μm using a sputtering method.

Next, a strain layer 233 made of a piezoelectric material such as PZT or PLZT is formed on the lower electrode 232 to a thickness of 0.1 μm to 1.0 μm using a sputtering or chemical vapor deposition (CVD) method. Subsequently, the strained layer 233 is phase shifted using a rapid heat treatment (RAT) method.

Subsequently, an upper electrode 234 made of a material having the same excellent electrical conductivity as that of the lower electrode 232 is formed on the strained layer 233 using a sputtering method.

Thereafter, the upper electrode 234, the strained layer 233, the lower electrode 232, and the membrane 231 are divided into respective actuators 230 in a cell unit. Pattern.

Then, the upper electrode 234, the strained layer 233, the lower electrode 232, the membrane 231, the etch stop layer 218, the upper protective layer 217, and the lower protective part from the portion where the drain pad 214a is formed. The vias 215 are sequentially etched to form via holes (not shown), and then metals such as tungsten (W), platinum (Pt), aluminum (Al), or titanium (Ti) are formed in the via holes. The front tube 235 is formed to connect the lower electrode 232 and the drain pad 214a by using a sputtering method. The lower tube 232 is electrically connected to the MOS transistor 220 of the driving substrate 210 by the lower electrode 232 of the actuator 230 through the drain pad 214a. To work.

Subsequently, as shown in FIG. 2D, a planarization material, Accuflo 241a, is formed on top of the actuator 230 and the exposed first sacrificial layer 220 by using a spin coating method. After coating to a thickness of about μm, the lower layer 241 is formed by depositing and diffusing a silencing agent 241b such as hexamethyldisilane (HMDS) or trimethyldisilane (TMDS) as an adhesive material thereon. Subsequently, the acuflo 242a is coated on the lower layer 241 to a thickness of about 1 μm to 2 μm by using a spin coating method, and then an adhesive material such as HMDS or TMDS is applied on the upper layer. The second sacrificial layer 240 having a multilayer structure is formed by depositing and diffusing the gent 242b to form the upper layer 242. Here, in another embodiment, the multi-layer structure of the second sacrificial layer 240 is not only a two-layer structure consisting of a lower layer and an upper layer, but also a lower layer and an intermediate layer, each layer consisting of alternating accucu and sillation agenda. It can also be composed of a three-layer structure consisting of a top layer, and the like.

Next, as shown in FIG. 2E, the second sacrificial layer 240 is partially etched to expose the actuator 230 using photolithography to form the mirror support part 245. do.

Subsequently, as illustrated in FIG. 2F, a material having excellent reflection characteristics such as Al is deposited on the second sacrificial layer 240 and the mirror support portion 245 by using a sputtering method, and then each actuator 230. ) To form one-to-one correspondence to form the mirror layer 250.

Finally, as shown in FIG. 2G, the second sacrificial layer 240 and the first sacrificial layer 220 are removed to complete the TMA device.

As described above, the manufacturing method of the two-layer thin film type optical path control device according to the present invention is to compensate for the fact that the surface of AccuFlo has a low adsorption force when the second sacrificial layer is formed by a plurality of coatings of AccuFlu, the flattening material. In addition, by depositing and diffusing a deposition agent (sylation agent) such as hexamethyldisilane (HMDS) or trimethyldisilane (TMDS) on the acuflo, it is possible to facilitate the subsequent manufacturing process by improving the adsorption power of the surface.

As described above, although the present invention has been described with reference to the drawings, those skilled in the art may variously modify and change the present invention without departing from the spirit and scope of the invention as set forth in the claims below. It will be appreciated.

Claims (5)

Providing a driving substrate including an insulating substrate, a MOS transistor, a diffusion barrier layer, a metal layer, a lower protective layer, a blocking layer, an upper protective layer, an etch stop layer, and the like; Forming a first sacrificial layer having an actuator support portion formed on the driving substrate; Forming an actuator having a membrane, a lower electrode, a deformation layer, an upper electrode, an electric tube, and the like formed on the first sacrificial layer and the actuator support part; Forming a second sacrificial layer of a multilayer in which an acuflo, which is a flattening material, and a sillation agent, which is an adhesive material, are alternately formed on the actuator and the exposed first sacrificial layer; Partially removing the second sacrificial layer to form an mirror support by exposing an actuator; Forming a mirror layer on the second sacrificial layer and the mirror support portion; And removing the second sacrificial layer and the first sacrificial layer. The method according to claim 1, wherein the silicide agent is made of hexamethyldisilane (HMDS). The method of claim 1, wherein the silicide agent is made of TMDS (trimethyldisilane). The method of claim 1, wherein the second sacrificial layer of the multilayer structure is a two-layer structure consisting of an upper layer and a lower layer, the lower layer is formed by depositing and spreading the silencing agenda on top of the acuflo coating, the upper layer is A method of manufacturing a two-layer thin film type optical path control apparatus, characterized in that the coating is formed on the upper layer of the lower layer, and then formed by depositing and spreading the silencing agenda on the upper layer. The method of claim 1, wherein the second sacrificial layer of the multi-layer structure is composed of a three-layer structure, such as a lower layer, an intermediate layer, an upper layer, each of the layer is characterized in that the accuflow and the silencing agenda are alternately. Method for manufacturing a thin film optical path control device having a two-layer structure.