INVESTORS RIGHTS AGREEMENT

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                                                                    Exhibit 4.20

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                           INVESTORS RIGHTS AGREEMENT

                          DATED AS OF NOVEMBER 18, 2005

                                      BETWEEN

                             AMKOR TECHNOLOGY, INC.

                                       AND

                           THE INVESTORS NAMED HEREIN

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                            INVESTORS RIGHTS AGREEMENT

     This Investors Rights Agreement (the "Agreement") is made and entered into
this 18th day of November, 2005, between Amkor Technology, Inc., a Delaware
corporation (the "Company"), and the individuals and entities (the "Investors")
listed on the signature pages to the Purchase Agreement (as defined below).

     This Agreement is made pursuant to the Note Purchase Agreement, dated as of
November 14, 2005, between the Company and the Investors (the "Purchase
Agreement"), which provides for the sale by the Company to the Investors of
$100,000,000 aggregate principal amount of the Company's 6 1/4% Convertible
Subordinated Notes due 2013 (the "Securities"). In order to induce the Investors
to enter into the Purchase Agreement, the Company has agreed to provide the
registration rights set forth in this Agreement. The execution of this Agreement
is a condition to the closing under the Purchase Agreement.

     In consideration of the foregoing, the parties hereto agree as follows:

     1.    Definitions.

     As used in this Agreement, the following capitalized defined terms shall
have the following meanings:

     "1933 Act" shall mean the Securities Act of 1933, as amended from time to
time.

     "1934 Act" shall mean the Securities Exchange Act of l934, as amended from
time to time.

     "1939 Act" shall mean the Trust Indenture Act of 1939, as amended from time
to time.

     "Affiliated Entities" shall mean James J. Kim and his estates, spouses,
ancestors and lineal descendants (and spouses thereof), the legal
representatives of any of the foregoing, and the trustee of any bona fide trust
of which one or more of the foregoing are sole beneficiaries or the grantors, or
any Person of which any of the forgoing, individually or collectively,
beneficially own (as defined in Rules 13d-3 and 13d-5 under the Exchange Act)
voting securities representing at least a majority of the total voting power of
all classes of Capital Stock of such Person (exclusive of any matters as to
which class voting rights exist).

     "Closing Date" shall mean the Closing as defined in the Purchase Agreement.

     "Common Stock" shall mean any shares of common stock, $0.001 par value, of
the Company and any other shares of common stock as may constitute "Common
Stock" for purposes of the Indenture.

     "Company" shall have the meaning set forth in the preamble and shall also
include the Company's successors.

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     "Depositary" shall mean The Depository Trust Company, or any other
depositary appointed by the Company, provided, however, that such depositary
must have an address in the Borough of Manhattan, in the City of New York.

     "Holder" shall mean each Investor, for so long as it owns any Registrable
Securities, and each of such Investor's successors, assigns and direct and
indirect transferees pursuant to the terms of this Agreement.

     "Indenture" shall mean the Indenture relating to the Securities, dated as
of November 18, 2005, between the Company and U.S. Bank National Association, as
trustee, as the same may be amended, supplemented, waived or otherwise modified
from time to time in accordance with the terms thereof.

     "Investors" shall have the meaning set forth in the preamble.

     "Majority Holders" shall mean the Holders of a majority of the aggregate
principal amount of outstanding Registrable Securities (assuming conversion of
all Securities into Common Stock); provided that whenever the consent or
approval of Holders of a specified percentage of Registrable Securities is
required hereunder, Registrable Securities held by the Company shall be
disregarded in determining whether such consent or approval was given by the
Holders of such required percentage amount.

     "Person" shall mean an individual, partnership (general or limited),
corporation, limited liability company, trust or unincorporated organization, or
a government or agency or political subdivision thereof.

     "Prospectus" shall mean the prospectus included in a Shelf Registration
Statement, including any preliminary prospectus, and any such prospectus as
amended or supplemented by any prospectus supplement, including any such
prospectus supplement with respect to the terms of the offering of any portion
of the Registrable Securities covered by a Shelf Registration Statement, and by
all other amendments and supplements to a prospectus, including post-effective
amendments, and in each case including all material incorporated by reference
therein.

     "Purchase Agreement" shall have the meaning set forth in the preamble.

     "Registrable Securities" shall mean all or any of the Securities issued
from time to time under the Indenture in registered form, and the shares of
Common Stock issuable upon conversion of such Securities; provided, however,
that any such Securities shall cease to be Registrable Securities when (i) a
Shelf Registration Statement with respect to such Securities shall have been
declared effective under the 1933 Act and such Securities shall have been
disposed of pursuant to such Shelf Registration Statement, (ii) such Securities
have been sold or transferred to the public pursuant to Rule l44, if available
(or any similar provision then in force, including Rule 144(k) but not Rule
144A) under the 1933 Act, or (iii) such Securities shall have ceased to be
outstanding.

     "Registration Expenses" shall mean any and all expenses incident to
performance of or compliance by the Company with this Agreement, including
without limitation: (i) all SEC, stock exchange or National Association of
Securities Dealers, Inc. (the "NASD") registration and filing


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fees, including, if applicable, the fees and expenses of any "qualified
independent underwriter" (and its counsel) that is required to be retained by
any holder of Registrable Securities in accordance with the rules and
regulations of the NASD, (ii) all fees and expenses incurred in connection with
compliance with state securities or blue sky laws and compliance with the rules
of the NASD (including reasonable fees and disbursements of counsel for any
underwriters or Holders in connection with blue sky qualification of any of the
Registrable Securities and any filings with the NASD), (iii) all expenses of the
Company in preparing or assisting in preparing, word processing, printing and
distributing any Shelf Registration Statement, any Prospectus, any amendments or
supplements thereto, any securities sales agreements and other documents
relating to the performance of and compliance with this Agreement, (iv) all fees
and expenses incurred in connection with the listing, if any, of any of the
Registrable Securities on any securities exchange or exchanges, (v) all rating
agency fees, (vi) the fees and disbursements of counsel for the Company and of
the independent public accountants of the Company, including in connection with
the Underwritten Offering the expenses of any special audits or "comfort"
letters required by or incident to such performance and compliance, (vii) the
reasonable fees and expenses of the Trustee, and any escrow agent or custodian,
(viii) the reasonable fees and expenses of a single counsel to the Holders in
connection with the Shelf Registration Statement, which counsel shall be
selected by the Majority Holders, and any fees and expenses of any special
experts retained by the Company in connection with any Shelf Registration
Statement, but excluding any underwriting discounts and commissions and transfer
taxes, if any, relating to the sale or disposition of Registrable Securities by
a Holder.

     "SEC" shall mean the United States Securities and Exchange Commission or
any successor agency or government body performing the functions currently
performed by the United States Securities and Exchange Commission.

     "Shelf Registration" shall mean a registration effected pursuant to Section
2.1 hereof.

     "Shelf Registration Statement" shall mean a "shelf" registration statement
of the Company pursuant to the provisions of Section 2.2 of this Agreement which
covers all of the Registrable Securities on an appropriate form under Rule 415
under the 1933 Act, or any similar rule that may be adopted by the SEC, and all
amendments and supplements to such registration statement, including
post-effective amendments, in each case including the Prospectus contained
therein, all exhibits thereto and all material incorporated by reference
therein.

     "Trustee" shall mean the trustee with respect to the Securities under the
Indenture.

     2.    Registration Under the 1933 Act.

           2.1   Shelf Registration.

               (a) Subject to Section 3(B)(b), the Company shall, at its cost,
no later than 90 days after the Closing Date, file with the SEC, and thereafter
shall use its commercially reasonable efforts to cause to be declared effective
as promptly as practicable but no later than 180 days after the Closing Date, a
Shelf Registration Statement relating to the offer and sale of the Registrable
Securities by the Holders that have provided the information pursuant to Section
2.1(d); provided, however, that in the event that the Company is eligible for,
and elects to utilize, the


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"automatic shelf" registration procedure on Form S-3 available to "well-known
seasoned issuers," the only obligation of the Company under this Section 2.1(a)
shall be to file a Shelf Registration Statement with the SEC no later than 120
days after the Closing Date, which Shelf Registration Statement shall become
immediately effective upon filing pursuant to the SEC rules adopted in Release
No. 33-8591; provided, further, that the Company may, upon written notice to all
Holders, defer the filing or the effectiveness of the Shelf Registration
Statement, or defer the filing of the Shelf Registration Statement if the
Company is eligible for, and elects to utilize, the "automatic shelf"
registration procedure, for a reasonable period not to exceed 45 days if the
Company is engaged in non-public negotiations or other non-public business
activities, disclosure of which would be required in such Shelf Registration
Statement (but would not be required if such Shelf Registration Statement were
not filed), and the Chief Financial Officer of the Company determines in good
faith that such disclosure would have a material adverse effect on the Company
and its subsidiaries taken as a whole.

               (b) The Company shall, at its cost, use its commercially
reasonable efforts, subject to Section 2.5, to keep the Shelf Registration
Statement continuously effective in order to permit the Prospectus forming part
thereof to be usable by Holders for a period of three years from the last date
of original issuance of any of the Securities, or for such shorter period that
will terminate when all Registrable Securities covered by the Shelf Registration
Statement have been sold pursuant to the Shelf Registration Statement or cease
to be outstanding or otherwise to be Registrable Securities (the "Effectiveness
Period").

               (c) Notwithstanding any other provisions hereof, the Company
shall use its commercially reasonable efforts to ensure that (i) any Shelf
Registration Statement and any amendment thereto and any Prospectus forming part
thereof and any supplement thereto complies in all material respects with the
1933 Act and the rules and regulations thereunder, (ii) any Shelf Registration
Statement and any amendment thereto does not, when it becomes effective, contain
an untrue statement of a material fact or omit to state a material fact required
to be stated therein or necessary to make the statements therein not misleading
and (iii) any Prospectus forming part of any Shelf Registration Statement, and
any supplement to such Prospectus (as amended or supplemented from time to
time), does not include an untrue statement of a material fact or omit to state
a material fact necessary in order to make the statements therein, in light of
the circumstances under which they were made, not misleading.

               (d) Notwithstanding any other provision hereof, no Holder of
Registrable Securities may include any of its Registrable Securities in the
Shelf Registration Statement pursuant to this Agreement unless such Holder
furnishes to the Company such information in writing as the Company may
reasonably request for use in connection with the Shelf Registration Statement
or Prospectus included therein and in any application to be filed with or under
state securities laws. Each Holder named as a selling securityholder in the
Prospectus agrees to promptly furnish to the Company all information required to
be disclosed in order to make information previously furnished to the Company by
the Holder not materially misleading and any other information regarding such
Holder and the distribution of such Holder's Registrable Securities as the
Company may from time to time reasonably request in writing.


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               (e) Each Holder agrees not to sell any Registrable Securities
pursuant to the Shelf Registration Statement without delivering, or causing to
be delivered, a Prospectus to the purchaser thereof and, following termination
of the Effectiveness Period, to notify the Company, within ten days of a written
request by the Company, of the amount of Registrable Securities sold pursuant to
the Shelf Registration Statement.

               The Company shall not permit any securities other than
Registrable Securities to be included in the Shelf Registration Statement. The
Company further agrees, if necessary, to supplement or amend the Shelf
Registration Statement, as required by Section 2.3(b) below, and to furnish to
the Holders of Registrable Securities copies of any such supplement or amendment
promptly after its being used or filed with the SEC.

          2.2 Expenses. The Company shall promptly pay all Registration Expenses
in connection with the registration pursuant to Section 2.1. Each Holder shall
pay all underwriting discounts and commissions and transfer taxes, if any,
relating to the sale or disposition of such Holder's Registrable Securities
pursuant to the Shelf Registration Statement.

          2.3 Effectiveness. A Shelf Registration Statement pursuant to Section
2.1 hereof will not be deemed to have become effective unless it has been
declared effective by the SEC; provided, however, that if, after it has been
declared effective, the offering of Registrable Securities pursuant to a Shelf
Registration Statement is interfered with by any stop order, injunction or other
order or requirement of the SEC or any other governmental agency or court, such
Shelf Registration Statement will be deemed not to have become effective during
the period of such interference, until the offering of Registrable Securities
pursuant to such Shelf Registration Statement may legally resume.

           2.4 Interest. In the event that (a) a Shelf Registration Statement is
not declared effective on or prior to November 18, 2006, (b) after
effectiveness, subject to Section 2.5, the Shelf Registration Statement fails to
be effective or usable by the Holders without being succeeded within seven
business days by a post-effective amendment or a report filed with the SEC
pursuant to the 1934 Act that cures the failure to be effective or usable, or
(c) the Shelf Registration Statement is unusable by the Holders for any reason,
and the aggregate number of days in any consecutive three-month or twelve-month
period, as applicable, for which the Shelf Registration Statement shall not be
usable exceeds the Suspension Period (as defined in Section 2.5 hereof) (each
such event being a "Registration Default"), additional interest, as liquidated
damages ("Liquidated Damages"), will accrue at a rate per annum of one-quarter
of one percent (0.25%) of the principal amount of the Securities for the first
90-day period from day following the Registration Default, and thereafter at a
rate per annum of one-half of one percent (0.50%) of the principal amount of the
Securities, provided that in no event shall Liquidated Damages accrue at a rate
per annum exceeding one half of one percent (0.50%) of the issue price of the
Securities; provided further that no Liquidated Damages shall accrue after the
third anniversary of the date of this Agreement; provided further that
Liquidated Damages shall not accrue under clauses (b) and (c) above with respect
to any Holder that is not named as a Selling Holder in the Shelf Registration
Statement; and provided further that no Liquidated Damages shall accrue if,
pursuant to Section 2.1(a) hereof, the Company defers the effectiveness of the
Shelf Registration Statement, for a reasonable period not to exceed 45 days if
the Company is engaged in non-public negotiations or other non-public business
activities, disclosure of


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which would be required in such Shelf Registration Statement (but would not be
required if such Shelf Registration Statement were not filed), and the Board of
Directors of the Company or a committee of the Board of Directors of the Company
determines in good faith that such disclosure would have a material adverse
effect on the Company and its subsidiaries taken as a whole. Upon the cure of
all Registration Defaults then continuing, the accrual of Liquidated Damages
will automatically cease and the interest rate borne by the Securities will
revert to the original interest rate at such time. Liquidated Damages shall be
computed based on the actual number of days elapsed in each 90-day period in
which the Shelf Registration Statement is not effective or is unusable. Holders
who have converted Securities into Common Stock will not be entitled to receive
any Liquidated Damages with respect to such Common Stock or the issue price of
the Securities converted.

          The Company shall notify the Trustee within three business days after
each and every date on which an event occurs in respect of which Liquidated
Damages are required to be paid. Liquidated Damages shall be paid by depositing
with the Trustee, in trust, for the benefit of the Holders of Registrable
Securities, on or before the applicable semiannual interest payment date,
immediately available funds in sums sufficient to pay the Liquidated Damages
then due. The Liquidated Damages due shall be payable on each interest payment
date to the record Holder of Registrable Securities entitled to receive the
interest payment to be paid on such date as set forth in the Indenture. Each
obligation to pay Liquidated Damages shall be deemed to accrue from and
including the day following the Registration Default to but excluding the day on
which the Registration Default is cured.

          A Registration Default under clause (a) above shall be cured on the
date that the Registration Statement is filed with the SEC. A Registration
Default under clause (b) above shall be cured on the date that the Shelf
Registration Statement is declared effective by the SEC. A Registration Default
under clauses (c) or (d) above shall be cured on the date an amended Shelf
Registration Statement is declared effective by the SEC or the Company otherwise
declares the Shelf Registration Statement and the Prospectus useable, as
applicable. The Company will have no liabilities for monetary damages with
respect to any Registration Default for which Liquidated Damages are expressly
provided for herein.

          2.5 Suspension. The Company may suspend the use of any Prospectus,
without incurring or accruing any obligation to pay Liquidated Damages pursuant
to Section 2.4 hereof, for a period not to exceed 45 calendar days in any
three-month period, or an aggregate of 90 calendar days in any twelve-month
period, (each, a "Suspension Period") if the Board of Directors of the Company
shall have determined in good faith that because of valid business reasons (not
including avoidance of the Company's obligations hereunder), including without
limitation proposed or pending corporate developments and similar events or
because of filings with the SEC, it is in the best interests of the Company to
suspend such use, and prior to suspending such use the Company provides the
Holders with written notice of such suspension, which notice need not specify
the nature of the event giving rise to such suspension. Each Holder shall keep
confidential any communications received by it from the Company regarding the
suspension of the use of the Prospectus, except as required by applicable law.

     3.    Registration Procedures.


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          (A) In connection with the obligations of the Company with respect to
the Shelf Registration, the Company shall:

               (a) prepare and file with the SEC a Shelf Registration Statement,
within the relevant time period specified in Section 2, on the appropriate form
under the 1933 Act, which form (i) shall be selected by the Company, (ii) shall
be available for the sale of the Registrable Securities by the selling Holders
thereof, (iii) shall comply as to form in all material respects with the
requirements of the applicable form and include or incorporate by reference all
financial statements required by the SEC to be filed therewith or incorporated
by reference therein, and (iv) shall comply in all respects with the applicable
requirements of Regulation S-T under the 1933 Act, if any, and use commercially
reasonable efforts to cause such Shelf Registration Statement to become
effective and remain effective in accordance with Section 2 hereof;

               (b) promptly prepare and file with the SEC such amendments and
post-effective amendments to the Shelf Registration Statement as may be
necessary under applicable law to respond to comments from the SEC and to keep
the Shelf Registration Statement effective for the Effectiveness Period, subject
to Section 2.4; and cause each Prospectus to be supplemented by any required
prospectus supplement, and as so supplemented to be filed pursuant to Rule 424
(or any similar provision then in force) under the 1933 Act and comply during
the Effectiveness Period with the provisions of the 1933 Act, the 1934 Act and
the rules and regulations thereunder required to enable the disposition of all
Registrable Securities covered by the Shelf Registration Statement in accordance
with the intended method or methods of distribution by the selling Holders
thereof;

               (c) (i) notify each Holder of Registrable Securities of the
filing, by issuing a press release, of a Shelf Registration Statement with
respect to the Registrable Securities; (ii) furnish to each Holder of
Registrable Securities that has provided the information required by Section
2.1(d) and to each underwriter of an underwritten offering of Registrable
Securities, if any, without charge, as many copies of each Prospectus, including
each preliminary Prospectus, and any amendment or supplement thereto and such
other documents as such Holder or underwriter may reasonably request, including
financial statements and schedules and, if the Holder so requests, all exhibits
in order to facilitate the unrestricted sale or other disposition of the
Registrable Securities; and (iii) subject to Section 2.4 hereof and to any
notice by the Company in accordance with Section 3(e) hereof of the existence of
any fact of the kind described in Sections 3(e)(ii), (iii), (iv), (v) and (vi)
hereof, hereby consent to the use of the Prospectus or any amendment or
supplement thereto by each of the selling Holders of Registrable Securities that
has provided the information required by Section 2.1(d) in connection with the
offering and sale of the Registrable Securities;

               (d) use commercially reasonable efforts to register or qualify
the Registrable Securities under all applicable state securities or "blue sky"
laws of such jurisdictions as any Holder of Registrable Securities covered by a
Shelf Registration Statement and each underwriter of an underwritten offering of
Registrable Securities shall reasonably request, and do any and all other acts
and things which may be reasonably necessary or advisable to enable each such
Holder and underwriter to consummate the disposition in each such jurisdiction
of such Registrable Securities owned by such Holder; provided, however, that the
Company shall not be required to (i) qualify as a foreign corporation or as a
dealer in securities in any jurisdiction where it would not


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otherwise be required to qualify