Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
343 words
A contactless, 5V only EPROM cell array formed in a silicon substrate, the EPROM cell array comprising: (a) an N+ source line formed in the silicon substrate; (b) first and second N+drain lines formed in parallel with and spaced-apart from the source line on opposite sides of the source line to define respective first and second substrate channel regions therebetween; (c) first and second field oxide strips formed in parallel with and spaced-apart from the first and second drain lines, respectively, such that the source line/drain line structure is isolated by the first and second field oxide strips to separate such structure from adjacent similar source/drain structures in the array; (d) a layer of first insulating material formed over the channel regions; (e) first and second array field oxide regions formed in the substrate between the first drain line and the source line and the second drain line and the source line, respectively; (f) first and second floating gates formed on the first insulating material and overlying a first portion of the corresponding first and second channel regions, respectively, that extends from an edge of the corresponding drain region to an intermediate point of the channel region thereby defining a second portion at the channel region that extends from the intermediate point to an edge of the source line and over which the floating gate does not extend, the floating gate including a coupling portion that extends over the corresponding array field oxide region; (g) a layer of second insulating material formed over the first and second floating gates, including the coupling portion thereof; (h) a conductive control gate line overlying the first and second floating gates but separated therefrom by the layer of second insulating material and comprising first and second access portions overlying the second portion of the first and second channel regions, respectively, but separated therefrom by the layer of first insulating material; and (i) a conductive coupling line overlying the coupling portion of the first and second floating gates but separated therefrom by the layer of second insulating material.
Claim 2
Dependent Claim
343 words
A contactless, 5V only EPROM cell array formed in a silicon substrate, the EPROM cell array comprising: (a) an N+ source line formed in the silicon substrate; (b) first and second N+drain lines formed in parallel with and spaced-apart from the source line on opposite sides of the source line to define respective first and second substrate channel regions therebetween; (c) first and second field oxide strips formed in parallel with and spaced-apart from the first and second drain lines, respectively, such that the source line/drain line structure is isolated by the first and second field oxide strips to separate such structure from adjacent similar source/drain structures in the array; (d) a layer of first insulating material formed over the channel regions; (e) first and second array field oxide regions formed in the substrate between the first drain line and the source line and the second drain line and the source line, respectively; (f) first and second floating gates formed on the first insulating material and overlying a first portion of the corresponding first and second channel regions, respectively, that extends from an edge of the corresponding drain region to an intermediate point of the channel region thereby defining a second portion at the channel region that extends from the intermediate point to an edge of the source line and over which the floating gate does not extend, the floating gate including a coupling portion that extends over the corresponding array field oxide region; (g) a layer of second insulating material formed over the first and second floating gates, including the coupling portion thereof; (h) a conductive control gate line overlying the first and second floating gates but separated therefrom by the layer of second insulating material and comprising first and second access portions overlying the second portion of the first and second channel regions, respectively, but separated therefrom by the layer of first insulating material; and (i) a conductive coupling line overlying the coupling portion of the first and second floating gates but separated therefrom by the layer of second insulating material.
Claim 3
Dependent Claim
16 words
An EPROM cell array as in claim 1 wherein the first insulating material is silicon dioxide.
Claim 4
Dependent Claim
18 words
An EPROM cell array as in claim 2 wherein the first and second floating gates comprise polycrystalline silicon.
Claim 5
Dependent Claim
20 words
An EPROM cell array as in claim 3 wherein the second insulating material comprises a composite layer of oxide-nitride-oxide (ONO).
Claim 6
Dependent Claim
20 words
An EPROM cell array as in claim 4 wherein both the control gate and the coupling line comprise polycrystalline silicon.