# US 6,132,814 A · Method for curing spin-on-glass film utilizing electron beam radiation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 6,132,814 A - Document ID: US6132814A - Status: Granted - Kind: A - Application number: 08/856,888 - Filed: 1997-05-14 - Granted: 2000-10-17 - Earliest claimed: 1995-05-08 - Assignees: Electron Vision Corporation - Inventors: William R. Livesay; Matthew F. Ross; Anthony L. Rubiales - Web page: https://patentgrep.com/patent/US6132814A ## CPC - H10P 95/00: Generic processes or apparatus for manufacture or treatments not covered by the other groups of this subclass - H10P 14/6342: {Liquid deposition, e.g. spin-coating, sol-gel techniques or spray coating} - H10P 14/6539: {by exposure to corpuscular radiation, e.g. exposure to electrons, alpha-particles, protons or ions} - H10P 14/6922: {the material containing Si, O and at least one of H, N, C, F or other non-metal elements, e.g. SiOC, SiOC:H or SiONC} - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 ## Abstract An electron beam exposure method is described which provides a means of curing spin-on-glass formed on a semiconductor wafer which insulates the conductive metal layer and planarizes the topography in the process of manufacturing multilayered integrated circuits. The method utilizes a large area, uniform electron beam exposure system in a soft vacuum environment. A wafer coated with uncured siloxane spin-on-glass is irradiated with electrons of sufficient energy to penetrate the entire thickness of the spin-on-glass and is simultaneously heated by infrared heaters. The wafer is exposed to a predetermined dose of electrons while simultaneously raised to a peak temperature in a soft vacuum environment. The electron beam and infrared heaters are then extinguished and the substrate cooled before removing from vacuum. ## Claims ### Claim 1 A method for curing spin-on-glass materials on a substrate, comprising the steps of: placing or leaving a spin-on-glass layer formed on a substrate; irradiating the spin-on-glass layer with a large-area electron beam; and continuing the irradiating step to reach a dose level sufficient to cure the spin-on-glass layer; wherein the irradiating step results in expulsion of carbon organic groups from the layer. ### Claim 2 (depends on 1) A method as defined in claim 1, wherein the irradiating step is continued to reach a dose level greater than approximately 2,500 .mu.C/cm.sup.2. ### Claim 3 (depends on 1) A method as defined in claim 1, wherein the irradiating step is continued to reach a dose level greater than approximately 2,500 to 10,000 .mu.C/cm.sup.2. ### Claim 4 (depends on 1) A method as defined in claim 1, wherein the spin-on-glass layer is cured without cracking or other damage. ### Claim 5 (depends on 1) A method as defined in claim 1, wherein the irradiating step further renders the layer less likely to absorb water. ### Claim 6 A method for curing spin-on-glass materials on a substrate, comprising the steps of: placing or leaving a spin-on-glass layer formed on a substrate; placing the substrate on a cooling plate; irradiating the spin-on-glass layer with a large-area electron beam at a dose level greater than approximately 2,500 .mu.C/cm.sup.2, and providing substantially uniform exposure of the surface of the spin-on-glass layer and having sufficient energy to penetrate the layer; continuing the irradiating step to reach a dose level sufficient to cure the spin-on-glass layer to such a degree that the layer attains enhanced physical properties relative to those obtained by thermal curing at a relatively low temperature; simultaneously applying heat to the spin-on-glass layer, as a result of energy supplied by the large-area electron beam; and maintaining the layer and the semiconductor substrate at a low temperature relative to those required for complete curing by thermal means, wherein the maintaining step is effected by means of the cooling plate; whereby the spin-on-glass layer is cured without cracking or other damage. ### Claim 7 (depends on 6) A method as defined in claim 6, wherein the spin-on-glass layer and the semiconductor substrate are maintained at a temperature below approximately 200.degree. C. ### Claim 8 (depends on 6) A method as defined in claim 6 wherein the irradiating step is continued to reach a dose level in the range of approximately 2,500 to 10,000 .mu.C/cm.sup.2. ### Claim 9 (depends on 6) A method as defined in claim 6, wherein the irradiating step results in expulsion of a carbon organic group material from the layer, which renders the layer less likely to absorb water. ### Claim 10 A method for curing spin-on-glass materials on a substrate, comprising the steps of: placing or leaving a spin-on-glass layer formed on a substrate; irradiating the spin-on-glass layer with a large-area electron beam at a dose level greater than approximately 2,500 .mu.C/cm.sup.2, generated in a vacuum chamber and providing substantially uniform exposure of the surface of the spin-on-glass layer and having sufficient energy to penetrate the layer; continuing the irradiating step to reach a dose level sufficient to cure the spin-on-glass layer; and simultaneously applying heat to the spin-on-glass layer, but maintaining the layer at a low temperature relative to those required for complete curing by thermal means; whereby the spin-on-glass layer is cured without cracking or other damage. ### Claim 11 (depends on 10) A method as set forth in claim 10, wherein the step of continuing the irradiating step cures the spin-on-glass layer to such a degree that the layer attains enhanced physical properties relative to those obtained by thermal curing at a relatively low temperature. ### Claim 12 (depends on 10) A method as defined in claim 10, wherein: the method is performed in a soft vacuum environment having a relatively high vacuum pressure in the range 10-40 millitorr. ### Claim 13 (depends on 10) A method as defined in claim 10, wherein: the curing process takes place at peak temperatures less than approximately 250.degree. C. ### Claim 14 (depends on 10) A method as defined in claim 10, wherein: the step of applying heat includes activating infrared heaters directed at the spin-on-glass layer. ### Claim 15 (depends on 10) A method as defined in claim 10, wherein: the step of applying heat includes heating the spin-on-glass solely as a result of energy supplied by the large-area electron beam. ### Claim 16 (depends on 10) A method as defined in claim 10, wherein the irradiating step results in expulsion of a carbon organic group material from the layer, which renders the layer less likely to absorb water after curing. ### Claim 17 (depends on 10) A method as defined in claim 10 wherein the irradiating step is continued to reach a dose level in the range of approximately 2,500 to 10,000 .mu.C/cm.sup.2. ### Claim 18 A method for curing spin-on-glass materials on a substrate, comprising the steps of: placing or leaving a spin-on-glass layer formed on a substrate; irradiating the spin-on-glass layer with a large-area electron beam at a dose level greater than approximately 2,500 .mu.C/cm.sup.2, and providing substantially uniform exposure of the surface of the spin-on-glass layer and having sufficient energy to penetrate the layer; continuing the irradiating step to reach a dose level sufficient to cure the spin-on-glass layer to such a degree that the layer attains enhanced physical properties relative to those obtained by thermal curing at a relatively low temperature; simultaneously applying heat to the spin-on-glass layer, but maintaining the layer at a low temperature relative to those required for complete curing by thermal means; maintaining in the vacuum chamber a soft vacuum having a relatively high vacuum pressure in the range of 10-40 millitorr, whereby any surface charge build-up, occurring as a result of electron irradiation of the spin-on-glass layer, is neutralized by positive ions formed near the surface of the layer; and inducing increased conductivity in the spin-on-glass layer, as a result of the impinging electron beam and increased temperature, whereby electrical charge is more readily dissipated from subsurface layers of spin-on-glass, and the occurrence of electron/hole traps associated with electron beam radiation is reduced or eliminated; and whereby the spin-on-glass layer is cured without cracking or other damage. ### Claim 19 A method for curing spin-on-glass materials on a substrate, comprising the steps of: placing or leaving a spin-on-glass layer formed on a substrate; irradiating the spin-on-glass layer with a large-area electron beam at a dose level greater than approximately 2,500 .mu.C/cm.sup.2 ; and continuing the irradiating step to reach a dose level sufficient to cure the spin-on-glass layer; whereby the spin-on-glass layer is cured without cracking or other damage. ### Claim 20 (depends on 19) A method as defined in claim 19, wherein the step of continuing the irradiating step cures the spin-on-glass layer to such a degree that the layer attains enhanced physical properties relative to those obtained by low-temperature thermal curing. ### Claim 21 (depends on 20) A method as defined in claim 20, wherein the step of continuing the irradiating step yields a cured spin-on-glass layer having a substantially lower proportion of carbon organic groups. ### Claim 22 (depends on 20) A method as defined in claim 20, wherein the step of continuing the irradiating step yields a cured spin-on-glass layer having a relatively high index of refraction. ### Claim 23 (depends on 20) A method as defined in claim 20, wherein the step of continuing the irradiating step yields a cured spin-on-glass layer that is relatively more dense. ### Claim 24 (depends on 19) A method as defined in claim 19, and further comprising: simultaneously applying heat to the spin-on-glass layer, but maintaining the layer at a low temperature relative to those required for complete curing by thermal means. ### Claim 25 (depends on 24) A method as defined in claim 24, wherein the step of applying heat includes activating infrared heaters directed at the spin-on-glass layer. ### Claim 26 (depends on 24) A method as defined in claim 24, wherein the step of applying heat includes heating the spin-on-glass layer solely as a result of energy supplied by the electron beam. ### Claim 27 (depends on 19) A method as defined in claim 19, wherein the irradiating step is performed using a large-area electron beam. ### Claim 28 (depends on 27) A method as defined in claim 27, wherein the large-area electron beam provides substantially uniform exposure of the spin-on-glass layer. ### Claim 29 (depends on 28) A method as defined in claim 28, wherein the large-area electron beam has sufficient energy to penetrate the entire thickness of the spin-on-glass layer. ### Claim 30 (depends on 19) A method as defined in claim 19, wherein the irradiating step is continued to reach a dose level greater than approximately 2,500 to 10,000 .mu.C/cm.sup.2.