Method of inspecting planarity of wafer surface after etchback step in integrated circuit fabrication
First Claim
1. A method of controlling an integrated circuit fabrication process, comprising the steps of:
- (a) performing a first step of integrated circuit fabrication on a wafer comprising the step of;
forming a first set of one or more material layers on said wafer; and
(b) performing a second sequence of integrated circuit fabrication steps on said wafer comprising the steps of;
scanning a predetermined area of said wafer'"'"'s surface with an atomic force microscope;
gathering surface height data from the atomic force microscope representing height with respect to position;
generating from the gathered surface height data at least one signal indicative of surface planarity;
comparing the at least one signal with predefined planarity criteria to determine if said forming step produced a surface that meets said predefined planarity criteria,
1 Assignment
0 Petitions
Accused Products
Abstract
An integrated circuit (IC) fabrication process involves forming electronic devices on a semiconductor substrate. A metal layer is deposited thereover and then patterned to interconnect the semiconductor devices. A dielectric layer is deposited over the metal layer and substrate. The dielectric layer is etched back to prepare for the deposition of additional metal and dielectric layers. The etched surface is scanned by an atomic force microscope (AFM) to gather data representing the wafer surface roughness. The data is evaluated by a computer to generate at least one surface roughness signal. Depending on the value of the surface roughness signal, the IC fabrication process continues with the next step, a remedial action is taken, the IC fabrication process is adjusted for subsequent wafers, or the wafer is discarded.
-
Citations
19 Claims
-
1. A method of controlling an integrated circuit fabrication process, comprising the steps of:
-
(a) performing a first step of integrated circuit fabrication on a wafer comprising the step of; forming a first set of one or more material layers on said wafer; and (b) performing a second sequence of integrated circuit fabrication steps on said wafer comprising the steps of; scanning a predetermined area of said wafer'"'"'s surface with an atomic force microscope; gathering surface height data from the atomic force microscope representing height with respect to position; generating from the gathered surface height data at least one signal indicative of surface planarity; comparing the at least one signal with predefined planarity criteria to determine if said forming step produced a surface that meets said predefined planarity criteria, - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. A method of controlling an integrated circuit fabrication process, comprising the steps of:
-
(a) performing a first sequence of integrated circuit fabrication steps on a wafer comprising the steps of; forming and patterning a first set of one or more material layers on said wafer, wherein the first set of layers is deposited and patterned in such manner to create hills and valleys therein; forming a second set of one or more material layers over said first set of material layers; etching back the deposited second set of material layers to produce a surface on the resulting wafer; (b) performing a second sequence of integrated circuit fabrication steps on said wafer comprising the steps of; scanning a predetermined area of said wafer'"'"'s surface with an atomic force microscope; gathering surface height data from the atomic force microscope representing height with respect to position; generating from the gathered surface height data at least one signal indicative of surface planarity; comparing the at least one signal with predefined planarity criteria to determine if said etching back step produced a surface that meets said predefined planarity criteria. - View Dependent Claims (11, 12, 13, 14, 15)
-
-
16. A method of controlling an integrated circuit fabrication process, comprising the steps of:
-
forming and patterning a first material layer on said wafer, wherein the first material layer is deposited and patterned in such manner to create hills and valleys therein; forming a second material layer over said first material layer; etching back the deposited second material layer to produce a surface on the resulting wafer; scanning a predetermined region of the wafer surface with an atomic force microscope; gathering data from the atomic force microscope representing height with respect to position; generating from the gathered data at least one signal indicative of surface roughness using a predetermined procedure; comparing the at least one signal indicative of surface roughness with predefined criteria; when the at least one signal is below a first predetermined threshold of the predetermined criteria, continuing with the integrated circuit fabrication process; when the at least one signal is within an intermediate range of said first predetermined threshold and a second predetermined threshold of the predetermined criteria, performing a remedial process on the wafer; and when the at least one signal is above said second predetermined threshold of the predetermined criteria, discarding the wafer. - View Dependent Claims (17, 18, 19)
-
Specification