# US 2008/0187481 A1 · High purity granular silicon > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2008/0187481 A1 - Document ID: US20080187481A1 - Status: Published application - Kind: A1 - Application number: 12/100,151 - Filed: 2008-04-09 - Published: 2008-08-07 - Earliest claimed: 2004-11-12 - Assignees: MEMC Electronic Materials, Inc. - Inventors: Jameel Ibrahim; Melinda Gayle Ivey; Timothy Dinh Truong - Web page: https://patentgrep.com/patent/US20080187481A1 ## CPC - C01B 33/027: by decomposition or reduction of gaseous or vaporised silicon compounds other than silica or silica-containing material - C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C} ## Abstract A high-purity semiconductor grade granular silicon composition, which can be produced in commercial quantities, is disclosed. In one embodiment the composition comprises a plurality of free-flowing particles having a total weight of at least about 300 kg and an average transition metal concentration of less than 0.2 ppba. In another embodiment the composition comprises a plurality of free-flowing silicon particles having a total weight of at least about 300 kg and at least 99 percent of the particles are between about 250 and 3500 microns in size. ## Claims ### Claim 1 A granular silicon composition comprising a plurality of free-flowing silicon particles having a total weight of at least about 300 kg, wherein the particles have an average transition metal concentration of less than 0.2 ppba. ### Claim 2 (depends on 1) The composition of claim 1 wherein the total weight of the particles is at least about one metric ton. ### Claim 3 (depends on 1) The composition of claim 1 wherein the particles have an average transition metal concentration between about 0.15 ppba and about 0.1 ppba. ### Claim 4 (depends on 1) The composition of claim 1 wherein the particles have an average boron concentration of no more than about 0.1 ppba. ### Claim 5 (depends on 1) The composition of claim 1 wherein the particles have an average phosphorous concentration of no more than about 0.1 ppba. ### Claim 6 (depends on 5) The composition of claim 5 wherein the particles have an average boron concentration of no more than about 0.1 ppba. ### Claim 7 (depends on 6) The composition of claim 6 wherein the particles have an average concentration of other donor contaminants of no more than about 0.03 ppba. ### Claim 8 (depends on 1) The composition of claim 1 wherein the particles have an average carbon concentration between about 0.02 and about 0.1 ppma. ### Claim 9 (depends on 1) The composition of claim 1 wherein the particles have an average hydrogen concentration between about 0.3 and about 1.5 ppmw. ### Claim 10 (depends on 1) The composition of claim 1 wherein the particles have an average size between about 800 and about 1200 microns. ### Claim 11 (depends on 1) The composition of claim 1 wherein at least 99 percent of the particles are between about 250 and about 3500 microns in size. ### Claim 12 (depends on 11) The composition of claim 11 wherein less than about 0.5 percent of the total weight of the particles is attributable to particles that are less than about 300 microns in size. ### Claim 13 (depends on 1) The composition of claim 1 wherein between about 0.006 and about 0.02 percent of the weight is attributable to surface dust. ### Claim 14 A granular silicon composition comprising a plurality of free-flowing silicon particles having a total weight of at least about 300 kg, wherein at least 99 percent of the particles are between about 250 and about 3500 microns in size. ### Claim 15 (depends on 17) The granular silicon composition of claim 17 wherein the total weight of the particles is at least one metric ton. ### Claim 16 (depends on 14) The composition of claim 14 wherein the particles have an average transition metal concentration of no more than about 0.1 ppba. ### Claim 17 (depends on 14) The composition of claim 14 wherein the particles have an average boron concentration of no more than about 0.1 ppba. ### Claim 18 (depends on 14) The composition of claim 14 wherein the particles have an average phosphorous concentration of no more than about 0.1 ppba. ### Claim 19 (depends on 18) The composition of claim 18 wherein the particles have an average boron concentration of no more than about 0.1 ppba. ### Claim 20 (depends on 19) The composition of claim 19 wherein the particles have an average concentration of other donor contaminants of no more than about 0.03 ppba. ### Claim 21 (depends on 14) The composition of claim 14 wherein the particles have an average carbon concentration between about 0.02 and about 0.1 ppma. ### Claim 22 (depends on 14) The composition of claim 14 wherein the particles have an average hydrogen concentration between about 0.3 and about 1.5 ppmw. ### Claim 23 (depends on 14) The composition of claim 14 wherein the particles have an average size between about 800 and about 1200 microns. ### Claim 24 (depends on 14) The composition of claim 14 wherein less than about 0.5 percent of the total weight of the particles is attributable to particles that are less than about 300 microns in size. ### Claim 25 (depends on 14) The composition of claim 14 wherein between about 0.006 and about 0.02 percent of the weight is attributable to surface dust.