Method of depositing insulating layer on underlying layer using plasma-assisted CVD process using pulse-modulated plasma

• US 5,231,057 A
• Filed: 08/20/1991
• Issued: 07/27/1993
• Est. Priority Date: 08/20/1990
• Status: Expired due to Term

• Current Assignee: Fujitsu Semiconductor Limited (Fujitsu Limited)
• Original Assignee: Fujitsu Limited
• Inventors: Furumura, Yuji, Nakahira, Junya, Doki, Masahiko
• Primary Examiner(s): Fourson, George
• Application Number:
  US07/748,955
• Time in Patent Office: 707 Days
• Field of Search: 437/225, 437/978, 437/238, 437/241, 437/245, 427/99, 427/47
• US Class Current: 438/637
• CPC Class Codes: C23C 16/515 using pulsed discharges
• CPC Class Codes: H01L 21/02129 the material being boron or phosphorus doped silicon oxides, e.g. BPSG, BSG or PSG
• CPC Class Codes: H01L 21/02164 the material being a silicon oxide, e.g. SiO2
• CPC Class Codes: H01L 21/0217 the material being a silicon nitride not containing oxygen, e.g. SixNy or SixByNz H01L21/02126 and H01L21/0214 take precedence
• CPC Class Codes: H01L 21/02274 in the presence of a plasma [PECVD]
• CPC Class Codes: H01L 21/0228 deposition by cyclic CVD, e.g. ALD, ALE, pulsed CVD
• CPC Class Codes: H01L 21/02337 treatment by exposure to a gas or vapour
• CPC Class Codes: H01L 21/31612 on a silicon body

Abstract

A method for producing a semiconductor device includes the steps of forming a patterned wiring line on a first insulating layer, and depositing a second insulating layer on the patterned wiring line and the first insulating layer by a plasma-assisted CVD process in which a pulse-modulated plasma is generated and a gas containing hydrogen is used.

Claims

1. A method comprising the steps of:

(a) forming a patterned wiring line on a first insulating layer; and

(b) depositing a second insulating layer on said patterned wiring line and said first insulating layer by a plasma-assisted CVD process employing a pulse-modulated plasma which is generated, in a space surrounded by a solenoid coil, by a magnetic field produced by the solenoid coil and the source gas contains hydrogen.

2. A method as claimed in claim 1, wherein said step (b) comprises the step of generating a pulse-modulated microwave in a chamber, said pulse-modulated microwave having a pulse width to cycle time ratio which is between approximately 50% and 80% and a cycle time of a selected value in the range of 4.0 ms to 10.0 ms.

3. A method as claimed in claim 2, wherein:

said step (b) further comprises simultaneously biasing a substrate which supports said first insulating layer by applying a pulse-modulated bias signal, which is synchronized with the pulse-modulated microwave, to said substrate; and

said pulse-modulated bias signal has a pulse width to cycle time ratio which is between approximately 50% and 80% and a cycle time of the same selected value in the range of 4.0 ms to 10.0 ms.

4. A method as claimed in claim 1, wherein step (b) comprises the step of generating said pulse-modulated plasma during successive ON intervals spaced by respective, alternate OFF intervals, each OFF interval being equal to or longer than approximately 0.5 ms.

5. A method as claimed in claim 1, wherein said method further comprises the step of annealing said first and second insulating layers and said patterned wiring line.

6. A method as claimed in claim 1, wherein said second insulating layer comprises silicon dioxide.

7. A method as claimed in claim 1, wherein said second insulating layer comprises silicon nitride.

8. A method as claimed in claim 1, wherein said second insulating layer comprises phospho-silicate glass.