Method of making silicon device with uniformly thick polysilicon

Claim 2

The process for forming polysilicon of a uniform thickness on a silicon semiconductor device comprising the steps of: (a) heating monocrystalline silicon in a vacuum to form a vapor of silicon; (b) exposing the silicon semiconductor device to the silicon vapor, thereby depositing amorphous silicon on said silicon semiconductor device; and (c) heating said device to a temperature sufficient to crystallize said amorphous silicon into polycrystalline silicon.

Claim 3

The process of claim 1 including the step of impregnating said vacuum deposited silicon with impurity atoms.

Claim 4

The process of claim 2 wherein said silicon is impregnated with impurities by ion implantation into said amorphous silicon, and wherein said amorphous silicon is crystallized by heat at a temperature of about 900° C.

Claim 5

The process of claim 1 wherein said device is heated in a gaseous atmosphere containing an impurity dopant.

Claim 6

The process of claim 1 including the steps of monitoring the thickness of said amorphous silicon and stopping said deposition when said amorphous silicon reaches a predetermined thickness.

Claim 7

In the manufacture of a silicon imaging device of the type having a silicon bulk and a transparent silicon dioxide overlay on the silicon bulk, the improvement comprising: (a) placing said device in a vacuum chamber; (b) heating monocrystalline silicon in said chamber when said chamber is evacuated to form within said chamber a vapor of silicon which, forms an amorphous deposit on said device; (c) monitoring the thickness of the silicon deposition on said device, and terminating the deposition of silicon when the deposition reaches a predetermined amount; and (d) heating said device to a temperature sufficient to crystallize said deposition into polycrystalline silicon of a uniform thickness.

Claim 8

In the manufacture of a silicon imaging device of the type having a silicon bulk and a transparent silicon dioxide overlay on the silicon bulk, the improvement comprising: (a) placing said device in a vacuum chamber; (b) heating monocrystalline silicon in said chamber when said chamber is evacuated to form within said chamber a vapor of silicon which, forms an amorphous deposit on said device; (c) monitoring the thickness of the silicon deposition on said device, and terminating the deposition of silicon when the deposition reaches a predetermined amount; and (d) heating said device to a temperature sufficient to crystallize said deposition into polycrystalline silicon of a uniform thickness.

Claim 9

In the improvement to the method of claim 6, the additional improvement of ion implanting impurity atoms into said deposition prior to crystallization of said deposition.